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A Comparison Of .net COBOL, Visual Basic and C#

, 17 Dec 2009 CC (ASA 2.5)
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A simple table showing the syntactic conversion from between each of these languages.

Introduction

If you are a COBOL programmer wanting to learn C# or a VB programmer wanting to learn COBOL as a .net language (or any other combination of VB.net, C# and COBOL) then this is a good place to start. 

Background

It has often been noted that the richness of the COBOL language in its Micro Focus .net implementation is not well known. Robert Sales and I have worked on this document to help bring the language to peoples' attention and to help people who need to work with COBOL on the .net platform 

Using the code 

All the examples where should work in the appropriate  Visual Studio IDE. You can get a free version here http://download.cnet.com/Net-Express-with-NET/3000-2069_4-10866201.html?part=dl-10866201&subj=dl&tag=button

VB.NET C# COBOL
Program Structure
Imports System
   Namespace Hello
   Class HelloWorld
      Overloads Shared Sub Main(ByVal args() As String)
         Dim name As String = "VB.NET"
         'See if an argument was passed from the command line
         If args.Length = 1 Then
            name = args(0)
         End If
         Console.WriteLine("Hello, " & name & "!")
      End Sub
   End Class
   End Namespace
End Class
using System;

namespace Hello 
{
   public class HelloWorld 
   {
      public static void Main(string[] args) 
      {
         string name = "C#";
         // See if an argument was passed from the command line
         if (args.Length == 1)
         {
            name = args[0];
         }
         Console.WriteLine("Hello, " + name + "!");
      }
   }
} 
      $set sourceformat(free)
      $set ilusing"System"
      *> Note, no direct syntax for specifying a default namespace;
class-id. HelloWorld as "Hello.Helloworld".
static.
  method-id. Main.
  local-storage section.
  01 nam string.
  procedure division using by value args as string occurs any.
      *> See if an argument was passed from the command line
      if args::"Length" = 1
          set nam to args(1)
      end-if
      display "Hello, ", nam, "!"
      *> or, if preferred...
      invoke type "Console"::"WriteLine"(string::"Concat"("Hello, ", nam, "!"))
   end method Main.
end static.
end class HelloWorld.
Comments
' Single line only
REM Single line only
''' <summary>XML comments</summary>
// Single line
/* Multiple
    line  */
/// <summary>XML comments on single line</summary>
/** <summary>XML comments on multiple lines</summary> */</span>

      * Single line only, "old-style" COBOL comment with '*' in column 7
               *> inline comment may follow Cobol statements etc.
         *>> <summary>XML comments</summary>
Data Types
Value Types
Boolean
Byte, SByte
Char
Short, UShort, Integer, UInteger, Long, ULong
Single, Double
Decimal
Date

Reference Types
Object
String

Initializing
Dim correct As Boolean = True
Dim b As Byte = &H2A   'hex
Dim o As Byte = &O52   'octal
Dim person As Object = Nothing
Dim name As String = "Dwight"
Dim grade As Char = "B"c
Dim today As Date = #12/31/2007 12:15:00 PM#
Dim amount As Decimal = 35.99@
Dim gpa As Single = 2.9!
Dim pi As Double = 3.14159265
Dim lTotal As Long = 123456L
Dim sTotal As Short = 123S
Dim usTotal As UShort = 123US
Dim uiTotal As UInteger = 123UI
Dim ulTotal As ULong = 123UL

Type Information
Dim x As Integer
Console.WriteLine(x.GetType())        ' Prints System.Int32
Console.WriteLine(GetType(Integer))   ' Prints System.Int32
Console.WriteLine(TypeName(x))        ' Prints Integer

Type Conversion
Dim d As Single = 3.5
Dim i As Integer = CType(d, Integer)   ' set to 4 (Banker's rounding)
i = CInt(d)   ' same result as CType
i = Int(d)    ' set to 3 (Int function truncates the decimal)
Value Types
bool
byte, sbyte
char
short, ushort, int, uint, long, ulong
float, double
decimal
DateTime   (not a built-in C# type)

Reference Types
object
string

Initializing
bool correct = true;
byte b = 0x2A;   // hex

object person = null;
string name = "Dwight";
char grade = 'B';
DateTime today = DateTime.Parse("12/31/2007 12:15:00");
decimal amount = 35.99m;
float gpa = 2.9f;
double pi = 3.14159265;
long lTotal = 123456L;
short sTotal = 123;
ushort usTotal = 123;
uint uiTotal = 123;
ulong ulTotal = 123;

Type Information
int x;
Console.WriteLine(x.GetType());        // Prints System.Int32
Console.WriteLine(typeof(int));        // Prints System.Int32
Console.WriteLine(x.GetType().Name);   // prints Int32

Type Conversion
float d = 3.5f;
int i = (int)d;   // set to 3  (truncates decimal)
Value Types
condition-value
binary-char (unsigned)
character
binary-short, binary-long, binary-double (unsigned)
float-short, float-long
decimal
DateTime (not a built-in COBOL type

Reference types
object
string

Initializing
01 correct condition-value value true.
01 b binary-char unsigned value h"2a".  *> Hex
01 o binary-char ussigned value o"52".  *> Octal
01 person object value null.
01 nam string value "Dwight".
01 grade character value "B".
01 today type "DateTime" value type "DateTime"::"Parse"("12/31/2007 12:15:00").
01 amount decimal value 35.99.
01 gpa float-short value 2.9.
01 pi float-long value 3.14159265.
01 lTotal binary-double value 123456.
01 sTotal binary-short value 123.
01 usTotal binary-short unsigned value 123.
01 uiTotal binary-long value 123.
01 ulTotal binary-long unsigned value 123.

Type Information
01 x binary-long.
display x::"GetType"          *> Prints System.Int32
display type of binary-long   *> Prints System.Int32
display x::"GetType"::"Name"  *> Prints Int32

Type Conversion
01 d float-short value 3.5.   *> automatic conversion
set i to d as binary-long     *> set to 3 (truncates decimal)

COBOL types not supported in C# or VB.Net
*> Only a few examples here
01 displayNumber pic 9(9).99.
01 computeNumber pic 9(9)V99.
01 alphaNumberic pic a(23).
01 binaryStorage pic x(12).
*> Also groups and redefines - a few examples
01 arecord.
   03 aSubRecord pic x(10).
   03 aUnion     pic 9(10) redefines aSubrecord.
Constants
Const MAX_STUDENTS As Integer = 25

' Can set to a const or var; may be initialized in a constructor
ReadOnly MIN_DIAMETER As Single = 4.93 
const int MAX_STUDENTS = 25;

// Can set to a const or var; may be initialized in a constructor
readonly float MIN_DIAMETER = 4.93f; 
78 MAX_STUDENTS value 25.  *> optionally public, binary-long...

*> Currently no direct COBOL equivalent of 'readonly'
Enumeration
Enum Action
  Start 
  [Stop]   ' Stop is a reserved word
  Rewind
  Forward
End Enum

Enum Status
  Flunk = 50
  Pass = 70
  Excel = 90
End Enum

Dim a As Action = Action.Stop
If a <> Action.Start Then _
   Console.WriteLine(a.ToString & " is " & a)     ' Prints "Stop is 1"

Console.WriteLine(Status.Pass)                    ' Prints 70
Console.WriteLine(Status.Pass.ToString())         ' Prints Pass
enum Action {Start, Stop, Rewind, Forward};
enum Status {Flunk = 50, Pass = 70, Excel = 90};

Action a = Action.Stop;
if (a != Action.Start)
  Console.WriteLine(a + " is " + (int) a);   // Prints "Stop is 1"

Console.WriteLine((int) Status.Pass);        // Prints 70
Console.WriteLine(Status.Pass);              // Prints Pass
   *> enum Action...      
   enum-id. Action.
      78 #Start.   *> Start is a reserved word
      78 #Stop.
      78 #Rewind.
      78 #Forward.
   end enum Action.
   *>enum Status...
   enum-id. Stat as "Status".
      78 Flunk value 50.
      78 Pass value 70.
      78 Excel value 90.
   end enum Action.
   display type "Status"::"Pass" as binary-long *> prints 70
   display type "Status"::"Pass" *> prints Pass

   
 
See demo program
Operators
Comparison
=  <  >  <=  >=  <>

Arithmetic
+  -  *  /
Mod
\  (integer division)
^  (raise to a power)

Assignment
=  +=  -=  *=  /=  \=  ^=  <<=  >>=  &=

Bitwise
And   Or   Xor   Not   <<   >>

Logical
AndAlso   OrElse   And   Or   Xor   Not

'Note: AndAlso and OrElse perform short-circuit logical evaluations

String Concatenation
& 
Comparison
==  <  >  <=  >=  !=

Arithmetic
+  -  *  /
%  (mod)
/  (integer division if both operands are ints)
Math.Pow(x, y)

Assignment
=  +=  -=  *=  /=   %=  &=  |=  ^=  <<=  >>=  ++  --

Bitwise
&   |   ^   ~   <<   >>

Logical
&&   ||   &   |   ^   !

//Note: && and || perform short-circuit logical evaluations

String Concatenation
+
Comparison
= < > <= >= <>

Arithmetic
+ - * /
function mod
*>no direct COBOL equivalent to integer division
**

Assignment
move, set, compute

Bitwise
b-and, b-or, b-xor, b-not, b-left, b-right

Logical
and, or, not
Choices
greeting = IIf(age < 20, "What's up?", "Hello")

' One line doesn't require "End If"
If age < 20 Then greeting = "What's up?" 
If age < 20 Then greeting = "What's up?" Else greeting = "Hello"

' Use : to put two commands on same line
If x <> 100 And y < 5 Then x *= 5 : y *= 2  


' Preferred
If x <> 100 And y < 5 Then
  x *= 5 
  y *= 2
End If


' To break up any long single line use _
If whenYouHaveAReally < longLine And _ 
  itNeedsToBeBrokenInto2 > Lines Then _
  UseTheUnderscore(charToBreakItUp)

If x > 5 Then 
  x *= y 
ElseIf x = 5 Then 
  x += y 
ElseIf x < 10 Then 
  x -= y 
Else 
  x /= y 
End If





Select Case color   ' Must be a primitive data type
  Case "pink", "red"
    r += 1 
  Case "blue" 
    b += 1 
  Case "green" 
    g += 1 
  Case Else 
    other += 1 
End Select
greeting = age < 20 ? "What's up?" : "Hello";

// Good practice is that all consequents are enclosed in {}
// or are on the same line as if.
if (age < 20) greeting = "What's up?";
else
{
   greeting = "Hello";
}

// Multiple statements must be enclosed in {}
if (x != 100 && y < 5) 
{   
  x *= 5;
  y *= 2;
}

//No need for _ or : since ; is used to terminate each statement.

if (x > 5) 
{
   x *= y; 
}
else if (x == 5) 
{
   x += y; 
}
else if (x < 10) 
{
   x -= y; 
}
else
{ 
   x /= y;
}

// Every case must end with break or goto case 
switch (color)                       // Must be integer or string
{
  case "pink":
  case "red":    r++;    break; 
  case "blue":   b++;    break;
  case "green":  g++;    break;
  default:    other++;   break;      // break necessary on default
}
*>greeting = age < 20 ? has no directly equivalent syntax in COBOL

if age < 20
   move "What's up?" to greeting
else
   move "Hello" to greeting
end-if



if x not = 100 and y < 5
   multiply 5 by x
   multiply 2 by y
end-if



*>No need for _ or : since statement is terminated by end-if
*> evalute is prefered in COBOL rather than if/else if/else
evaluate x
   when > 5
      multiply y by x
   when 5
      add y to x
   when < 10
      subtract y from x
   when other
      divide y into x
end-evaluate







evaluate color   *> can be any type
   when "pink"
   when "red"
      add 1 to r
   when "blue"
      add 1 to b
   when "green"
      add 1 to g
   when other
      add 1 to other-color
end-evaluate
               
See demo program
Loops
Pre-test Loops:
While c < 10 
  c += 1 
End While   
Do Until c = 10 
  c += 1 
Loop

Do While c < 10 
  c += 1 
Loop   
For c = 2 To 10 Step 2 
  Console.WriteLine(c) 
Next


Post-test Loops:
Do 
  c += 1 
Loop While c < 10   Do 
  c += 1 
Loop Until c = 10

Array or collection looping
Dim names As String() = {"Fred", "Sue", "Barney"} 
For Each s As String In names 
  Console.WriteLine(s) 
Next



Breaking out of loops
Dim i As Integer = 0
While (True)
   If (i = 5) Then
      Exit While
   End If
   i += 1
End While 



Continue to next iteration
For i = 0 To 4
   If i < 4 Then
      Continue For
   End If
   Console.WriteLine(i)   ' Only prints 4
Next
Pre-test Loops:
// no "until" keyword
while (c < 10) 
{
   c++;
}
  
  



for (c = 2; c <= 10; c += 2) 
{
   Console.WriteLine(c);
}

Post-test Loop:
do
{ 
  c++; 
} while (c < 10);


Array or collection looping
string[] names = {"Fred", "Sue", "Barney"};
foreach (string s in names)
{
   Console.WriteLine(s);
}


Breaking out of loops
int i = 0;
while (true) 
{
  if (i == 5) 
  {
      break;
  }
  i++;
}

Continue to next iteration
for (i = 0; i < 5; i++) 
{
  if (i < 4)
  {
    continue;
  }
  Console.WriteLine(i);   // Only prints 4
}
Pre-test loops:
*> No WHILE keyword
perform until c >= 10
   add 1 to c
end-perform

perform varying c from 2 by 2 until c > 10
   display c
end-perform







Post-test loops:
perform with test after until c >= 10
   add 1 to c
end-perform



Array or collection looping
01 names string occurs any.
01 s string.
set content of names to ("Fred" "Sue" "Barney")
perform varying s through names
   display s
end-perform

Breaking out of loops:
01 i binary-long value 0.
perform until exit
   if i = 5
      exit perform
   end-if
   add 1 to i
end-perform



Continue to next iteration:
01 i binary-long value 0
perform varying i from 0 by 1 until i >= 5
   if i < 4
      exit perform cycle
   end-if
   display i *>Only prints 4
end-perform

See demo program
Arrays
Dim nums() As Integer = {1, 2, 3} 
For i As Integer = 0 To nums.Length - 1 
   Console.WriteLine(nums(i)) 
Next 

' 4 is the index of the last element, so it holds 5 elements
Dim names(4) As String 
names(0) = "David"
names(5) = "Bobby"  ' Throws System.IndexOutOfRangeException 

' Resize the array, keeping the existing values (Preserve is optional)
' Note however, that this produces a new copy of the array - it is not an in-place resize!

ReDim Preserve names(6)




Dim twoD(rows-1, cols-1) As Single 
twoD(2, 0) = 4.5

Dim jagged()() As Integer = { _ 
  New Integer(4) {}, New Integer(1) {}, New Integer(2) {} } 
jagged(0)(4) = 5
int[] nums = {1, 2, 3};
for (int i = 0; i < nums.Length; i++)
{
   Console.WriteLine(nums[i]);
}

// 5 is the size of the array
string[] names = new string[5];
names[0] = "David";
names[5] = "Bobby";   // Throws System.IndexOutOfRangeException 


// C# can't dynamically resize an array.  Just copy into new array.
string[] names2 = new string[7]; 
Array.Copy(names, names2, names.Length);   // or names.CopyTo(names2, 0); 



float[,] twoD = new float[rows, cols];
twoD[2,0] = 4.5f; 

int[][] jagged = new int[3][] { 
  new int[5], new int[2], new int[3] };
jagged[0][4] = 5;
01 nums binary-long occurs any values 1, 2, 3.
*> Can also do:
set content of nums to (1 2 3)

*> 5 is the size of the array
01 names string occurs 5.
*> Can also do:
01 names string occurs any.
set size of names to 5
set names(1) to "David"  *> first element indexed as 1
set names(6) to "Bobby"  *> throws System.IndexOutOfRangeException

*> COBOL cannot resize an array - use copy
01 names2 string occurs 7.
invoke type "Array"::"Copy"(names, names2, names::"Length")
*> or else:
invoke names::"CopyTo"(names2, 0)

01 twoD float-short occurs any, any.
set size of twoD to rows, cols

01 jagged binary-long occurs any, occurs any.
set size of jagged to 3
set size of jagged(1) to 5
set jagged(1 5) to 5

See demo program
Functions
' Pass by value (in, default), reference (in/out), and reference (out)
Sub TestFunc(ByVal x As Integer, ByRef y As Integer, ByRef z As Integer)
  x += 1
  y += 1 
  z = 5 
End Sub


Dim a = 1, b = 1, c As Integer   ' c set to zero by default
TestFunc(a, b, c) 
Console.WriteLine("{0} {1} {2}", a, b, c)   ' 1 2 5






' Accept variable number of arguments 
Function Sum(ByVal ParamArray nums As Integer()) As Integer 
  Sum = 0  
  For Each i As Integer In nums 
    Sum += i 
  Next 
End Function   ' Or use Return statement like C#

Dim total As Integer = Sum(4, 3, 2, 1)   ' returns 10













' Optional parameters must be listed last and must have a default value
Sub SayHello(ByVal name As String, Optional ByVal prefix As String = "")
  Console.WriteLine("Greetings, " & prefix & " " & name) 
End Sub

SayHello("Strangelove", "Dr.")
SayHello("Madonna")
// Pass by value (in, default), reference (in/out), and reference (out)
void TestFunc(int x, ref int y, out int z) 
{
   x++;  
   y++;
   z = 5;
}

int a = 1, b = 1, c;  // c doesn't need initializing
TestFunc(a, ref b, out c);
Console.WriteLine("{0} {1} {2}", a, b, c);  // 1 2 5






// Accept variable number of arguments
int Sum(params int[] nums) 
{
  int sum = 0;
  foreach (int i in nums)
  {
      sum += i;
  }
  return sum;
}

int total = Sum(4, 3, 2, 1);   // returns 10










/* C# doesn't support optional arguments/parameters.  
   Just create two different versions of the same function. */  
void SayHello(string name, string prefix) 
{
   Console.WriteLine("Greetings, " + prefix + " " + name);
} 

void SayHello(string name) 
{ 
   SayHello(name, ""); 
}
method-id. TestFunc.
   procedure division using by value x as binary-long, 
                            by reference y as binary-long, 
                            output z as binary-long.
      add 1 to x, y
      move 5 to z
end method TestFunc.

01 a binary-long value 1.
01 b binary-long value 1.
01 c binary-long.  *> c doesn't need initializing

invoke self::"TestFunc"(value a reference b output c)
*> Or 
invoke self::"TestFunc"(a b c)
display a space b space c

*> sum is an intrinsic function in COBOL
01 total binary-long.
set total to function sum(4 3 2 1) *> returns 10

*> To create a non intrinsic variable argument list function:
Method-id. MySum.
01 i binary-long.
Procedure division using params nums as binary-long occurs any
                      returning mysum as binary-long.
    Perform varying i through nums
        Add i to mysum
    End-perform
    Goback
End method MySum.

*> then to call it:
method-id. main.
01 i binary-long.
    set i to self::"MySum"(1 2 3 4)
    display i
end method main.

*> COBOL doesn't support optional arguments/parameters.
*> Just create two different versions of the same function.  
method-id. SayHello.
   procedure division using by value nam as string, prefix as string.
      display "Greetings, " prefix space nam
   end method SayHello.

method-id. SayHello.
   procedure division using by value nam as string.
      invoke self::"SayHello"(nam "")
end method SayHello.

See demo program A See demo program B
Strings
Special character constants (all also accessible from ControlChars class)
vbCrLf, vbCr, vbLf, vbNewLine
vbNullString
vbTab
vbBack
vbFormFeed
vbVerticalTab
""

' String concatenation (use & or +)
Dim school As String = "Harding" & vbTab
school = school & "University" ' school is "Harding (tab) University"

' Chars
Dim letter As Char = school.Chars(0)      ' letter is H
letter = Convert.ToChar(65)               ' letter is A
letter = Chr(65)                          ' same thing
Dim word() As Char = school.ToCharArray() ' word holds Harding



' No string literal operator
Dim msg As String = "File is c:\temp\x.dat"



' String comparison
Dim mascot As String = "Bisons"
If (mascot = "Bisons") Then                  ' true
If (mascot.Equals("Bisons")) Then            ' true
If (mascot.ToUpper().Equals("BISONS")) Then  ' true
If (mascot.CompareTo("Bisons") = 0) Then     ' true

' String matching with Like - Regex is more powerful
If ("John 3:16" Like "Jo[Hh]? #:*") Then   'true

' Substring
s = mascot.Substring(2, 3)) ' s is "son"

' Replacement
s = mascot.Replace("sons", "nomial")) ' s is "Binomial"

' Split
Dim names As String = "Frank,Becky,Ethan,Braden"
Dim parts() As String = names.Split(",".ToCharArray())   ' One name in each slot


' Date to string
Dim dt As New DateTime(1973, 10, 12)
Dim s As String = "My birthday: " & dt.ToString("MMM dd, yyyy")   ' Oct 12, 1973

' Integer to String
Dim x As Integer = 2
Dim y As String = x.ToString()     ' y is "2"

' String to Integer
Dim x As Integer = Convert.ToInt32("-5")     ' x is -5




' Mutable string
Dim buffer As New System.Text.StringBuilder("two ")
buffer.Append("three ")
buffer.Insert(0, "one ")
buffer.Replace("two", "TWO")
Console.WriteLine(buffer)         ' Prints "one TWO three" 
Escape sequences
\r    // carriage-return
\n    // line-feed
\t    // tab
\\    // backslash
\"    // quote



// String concatenation
string school = "Harding\t";
school = school + "University";   // school is "Harding (tab) University"

// Chars
char letter = school[0];              // letter is H
letter = Convert.ToChar(65);          // letter is A
letter = (char)65;                    // same thing
char[] word = school.ToCharArray();   // word holds Harding



// String literal
string msg = @"File is c:\temp\x.dat";
// same as
string msg = "File is c:\\temp\\x.dat";

// String comparison
string mascot = "Bisons";
if (mascot == "Bisons")                 // true
if (mascot.Equals("Bisons"))            // true
if (mascot.ToUpper().Equals("BISONS"))  // true
if (mascot.CompareTo("Bisons") == 0)    // true

// String matching - No Like equivalent, use Regex


// Substring
s = mascot.Substring(2, 3))     // s is "son"

// Replacement
s = mascot.Replace("sons", "nomial"))     // s is "Binomial"

// Split
string names = "Frank,Becky,Ethan,Braden";
string[] parts = names.Split(",".ToCharArray());   // One name in each slot


// Date to string
DateTime dt = new DateTime(1973, 10, 12);
string s = dt.ToString("MMM dd, yyyy");     // Oct 12, 1973

// int to string
int x = 2;
string y = x.ToString();     // y is "2"

// string to int
int x = Convert.ToInt32("-5");     // x is -5




// Mutable string
System.Text.StringBuilder buffer = new System.Text.StringBuilder("two ");
buffer.Append("three ");
buffer.Insert(0, "one ");
buffer.Replace("two", "TWO");
Console.WriteLine(buffer);     // Prints "one TWO three"
Escape sequences
x"0a"  *> line-feed
x"09"  *> tab
"\"    *> backslash
""     *> quote




*> string concatenation
01 school string value "Harding" & x"09".
    set school to string::"Concat"(school, "University")  *> school is "Harding (tab) University"

*> Chars
01 letter character.
01 word character occurs any.
    set letter to school::"Chars"(0)   *> letter is H
    set letter to type "Convert"::"ToChar"(65) *> letter is A
    set letter to 65 as character      *> same thing
    set word to school::"ToCharArray"  *>word holds Harding

*> String literal
01 msg string value "File is c:\temp\x.dat".



*>String comparison
01 mascot string value "Bisons".
    if mascot = "Bisons"    *> true
    if mascot::"Equals"("Bisons")  *> true
    if mascot::"ToUpper"::"Equals"("BISONS")  *> true
    if mascot::"CompareTo"("Bisons") = 0  *> true

*> String matching - no Like equivalent , use Regex


*> Substring
    set s to mascot::"Substring"(2 3) *> s is "son"

*> Replacement
    set s to mascot::"Replace"("sons" "nomial")  *> s is "Binomial"

*> Split
01 names string value "Frank,Becky,Ethan,Braden".
01 parts string occurs any.
    set parts to names::"Split"(",")

*> Date to string
01 dt type "DateTime" value new "DateTime"(1973, 10, 12).
01 s string.
    set s to dt::"ToString"("MMM dd, yyyy")  *> Oct 12, 1973

*> int to string
01 x string.
01 y binary-long value 2.
    set x to type x::"ToString"   *> x is "2"
        
*> string to int
01 x binary-long.
    set x to type "Convert"::"ToInt32"("-5")   *> x is -5
    
*> Mutable string
01 buffer type "System.Text.StringBuilder" value new "System.Text.StringBuilder"("two ").
    invoke buffer::"Append"("three ")
    invoke buffer::"Insert"(0, "one ")
    invoke buffer::"Replace("two" "TWO"
    display buffer   *> Prints "one TWO three"
    
See demo program
Exception Handling
' Throw an exception
Dim ex As New Exception("Something is really wrong.")
Throw  ex 

' Catch an exception
Try 
  y = 0
  x = 10 / y
Catch ex As Exception When y = 0 ' Argument and When is optional
  Console.WriteLine(ex.Message)
Finally
  Beep()
End Try

' Deprecated unstructured error handling
On Error GoTo MyErrorHandler
...
MyErrorHandler: Console.WriteLine(Err.Description)
// Throw an exception
Exception up = new Exception("Something is really wrong.");
throw up;  // ha ha

// Catch an exception
try 
{ 
  y = 0;
  x = 10 / y;
}
catch (Exception ex) // Argument is optional, no "When" keyword 
{
  Console.WriteLine(ex.Message);
}
finally 
{
  Microsoft.VisualBasic.Interaction.Beep();
} 
*> Throw an exception
01 up type "Exception" value new "Exception"("Something is really wrong.");
raise up  *> ha ha

*> Catch an exception
try
  set y to 0;
  compute x = 10 / y
catch (type "Exception" ex)   *> Argument is optional, no "When" keyword 
  display ex.Message
finally
  invoke type "Microsoft.VisualBasic.Interaction"::"Beep"
end-try

See demo program
Namespaces
Namespace Harding.Compsci.Graphics 
  ...
End Namespace

' or

Namespace Harding
  Namespace Compsci
    Namespace Graphics 
      ...
    End Namespace
  End Namespace
End Namespace

Imports Harding.Compsci.Graphics 
namespace Harding.Compsci.Graphics 
{
  ...
}

// or

namespace Harding 
{
  namespace Compsci 
  {
    namespace Graphics 
    {
      ...
    }
  }
}

using Harding.Compsci.Graphics;
*> At the file level
$set ilnamespace "Harding.Compsci.Graphics"

*> The directive can also be set as a project
*> level to apply the name space to all classes in the project.










Classes / Interfaces
' Accessibility keywords 
Public
Private
Friend                    
Protected
Protected Friend
Shared

' Inheritance
Class FootballGame
  Inherits Competition
  ...
End Class 

' Interface definition
Interface IAlarmClock 
  ...
End Interface

' Extending an interface 
Interface IAlarmClock 
  Inherits IClock
  ...
End Interface

' Interface implementation
Class WristWatch 
  Implements IAlarmClock, ITimer 
   ...
End Class
//Accessibility keywords 
public
private
internal
protected
protected internal
static

// Inheritance
class FootballGame : Competition 
{
  ...
}


// Interface definition
interface IAlarmClock 
{
  ...
}

// Extending an interface 
interface IAlarmClock : IClock 
{
  ...
}


// Interface implementation
class WristWatch : IAlarmClock, ITimer 
{
   ...
}
*> Accessibility keywords
public
private
internal
protected
protected internal
static

*> Inheritance
class-id. FootballGame inherits type "Competition".
  ...
end class FootballGame.


*> Interface definition
interface-id. IAlarmClock.
  ...
end interface IAlarmClock.

*> Extending an interface 
interface-id IAlarmClock extends type "IClock".
  ...
end interface IAlarmClock.


*> Interface implementation
class-id. WristWatch implements type "IAlarmClock", type "ITimer".
   ...
end class WristWatch.

See demo program
Constructors / Destructors
Class SuperHero
  Private _powerLevel As Integer 

  Public Sub New() 
    _powerLevel = 0 
  End Sub 

  Public Sub New(ByVal powerLevel As Integer) 
    Me._powerLevel = powerLevel 
  End Sub

  Protected Overrides Sub Finalize() 
   ' Desctructor code to free unmanaged resources 
    MyBase.Finalize() 
  End Sub
End Class
class SuperHero 
{
  private int _powerLevel;

  public SuperHero() 
  {
     _powerLevel = 0;
  }

  public SuperHero(int powerLevel) 
  {
    this._powerLevel= powerLevel; 
  }

  ~SuperHero() 
  {
    // Destructor code to free unmanaged resources.
    // Implicitly creates a Finalize method
  }
}
class-id. SuperHero.
01 _powerLevel binary-long.

method-id. new.
procedure division.
    set _powerLevel to 0
end method new.

method-id. new.
procedure division using by value powerLevel as binary-long.
    set _powerLevel to powerLevel
end method new.

method-id. Finalize override protected.
    *> Destructor code to free unmanaged resources.
end method Finalize.
end class SuperHero.

See demo program
Using Objects
Dim hero As SuperHero = New SuperHero
' or
Dim hero As New SuperHero

With hero 
  .Name = "SpamMan" 
  .PowerLevel = 3 
End With 
hero.Defend("Laura Jones") 
hero.Rest()     ' Calling Shared method
' or
SuperHero.Rest()

Dim hero2 As SuperHero = hero  ' Both reference the same object 
hero2.Name = "WormWoman" 
Console.WriteLine(hero.Name)   ' Prints WormWoman

hero = Nothing    ' Free the object

If hero Is Nothing Then _ 
  hero = New SuperHero

Dim obj As Object = New SuperHero 
If TypeOf obj Is SuperHero Then _
  Console.WriteLine("Is a SuperHero object.")

  
  
  
  
  
' Mark object for quick disposal
Using reader As StreamReader = File.OpenText("test.txt")
  Dim line As String = reader.ReadLine()
  While Not line Is Nothing
    Console.WriteLine(line)
    line = reader.ReadLine()
  End While
End Using
SuperHero hero = new SuperHero(); 



// No "With" construct
hero.Name = "SpamMan"; 
hero.PowerLevel = 3; 


hero.Defend("Laura Jones");
SuperHero.Rest();   // Calling static method



SuperHero hero2 = hero;   // Both reference the same object 
hero2.Name = "WormWoman"; 
Console.WriteLine(hero.Name);   // Prints WormWoman

hero = null ;   // Free the object

if (hero == null)
  hero = new SuperHero();

Object obj = new SuperHero(); 
if (obj is SuperHero)
{ 
  Console.WriteLine("Is a SuperHero object.");
} 
  
  
  
// Mark object for quick disposal
using (StreamReader reader = File.OpenText("test.txt")) 
{
  string line;
  while ((line = reader.ReadLine()) != null)
  {
    Console.WriteLine(line);
  }
}
01 hero type "SuperHero" value new "SuperHero".
01 hero2 type "SuperHero".
01 obj object.
01 reader type "StreamReader".
01 lin string.

// No "With" construct
set hero::"Name" to "SpamMan"
set hero::"PowerLevel" to 3


invoke hero::"Defend"("Laura Jones")
invoke type "SuperHero"::"Rest"   *> Calling static method



set hero2 to hero      *> Both reference the same objectv
set hero2::"Name" to "WormWoman"
display hero::"Name"   *> Prints WormWoman

set hero to null       *> Free the object

if hero = null
    set hero to new "SuperHero"
end-if

set obj to new "SuperHero"
if obj is instance of type "SuperHero"
    display "Is a SuperHero object."
end-if

*> No 'using' construct in COBOL
try
    set reader to type "File"::"OpenText"("test.txt")
    perform until exit
        set lin to reader::"ReadLine"
        if lin = null
            exit perform
        end-if
    end-perform
finally
    if reader not = null
        invoke reader::"Dispose"
    end-if
end-try

See demo program
Structs
Structure StudentRecord 
  Public name As String 
  Public gpa As Single 

  Public Sub New(ByVal name As String, ByVal gpa As Single) 
    Me.name = name 
    Me.gpa = gpa 
  End Sub 
End Structure

Dim stu As StudentRecord = New StudentRecord("Bob", 3.5) 
Dim stu2 As StudentRecord = stu   

stu2.name = "Sue" 
Console.WriteLine(stu.name)    ' Prints Bob
Console.WriteLine(stu2.name)   ' Prints Sue
struct StudentRecord 
{
  public string name;
  public float gpa;

  public StudentRecord(string name, float gpa) 
  {
    this.name = name;
    this.gpa = gpa;
  }
}
StudentRecord stu = new StudentRecord("Bob", 3.5f);
StudentRecord stu2 = stu;  

stu2.name = "Sue";
Console.WriteLine(stu.name);    // Prints Bob
Console.WriteLine(stu2.name);   // Prints Sue
      $set sourceformat(free) preservecase
valuetype-id. StudentRecord.
object.
01 #name string public.
01 gpa float-short public.
method-id. new.
procedure division using by value nam as string, gpa as float-short.
    set #name to nam
    set self::"gpa" to gpa
end method new.
end object.
end valuetype StudentRecord.

class-id. a.
static.
method-id. main.
01 stu type "StudentRecord" value new "StudentRecord"("Bob", 3.5).
01 stu2 type "StudentRecord".
procedure division.
    set stu2 to stu
    set stu2::"name" to "Sue"
    display stu::"name"   *> Prints Bob
    display stu2::"name"  *> Prints Sue
end method main.
end static.
end class a.

See demo program
Properties
Private _size As Integer

Public Property Size() As Integer
  Get 
    Return _size 
  End Get 
  Set (ByVal Value As Integer) 
    If Value < 0 Then 
      _size = 0 
    Else 
      _size = Value 
    End If 
  End Set 
End Property

foo.Size += 1
private int _size;

public int Size 
{ 
  get 
  { 
    return _size; 
  } 
  set 
  { 
    if (value < 0)
    {    
      _size = 0; 
    }
    else
    {    
      _size = value; 
    }
  } 
}
foo.Size++;
      $set sourceformat(free) preservecase
class-id. MyClass.
object.
01 _size binary-long private.
method-id. get property #Size.
procedure division returning ret as binary-long.
    set ret to _size
end method.
method-id. set property #Size.
procedure division using by value val as binary-long.
    if val < 0
        set _size to 0
    else
        set _size to val
    end-if
end method.
end object.
end class MyClass.

class-id. a.
static.
method-id. main.
01 foo type "MyClass" value new"MyClass".
    add 1 to foo::"Size"
    display foo::"Size"
end method main.
end static.
end class a.

See demo program
Delegates / Events
Delegate Sub MsgArrivedEventHandler(ByVal message As String)

Event MsgArrivedEvent As MsgArrivedEventHandler







' or to define an event which declares a delegate implicitly
Event MsgArrivedEvent(ByVal message As String)

AddHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback 
' Won't throw an exception if obj is Nothing
RaiseEvent MsgArrivedEvent("Test message") 
RemoveHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback
Imports System.Windows.Forms

Dim WithEvents MyButton As Button   ' WithEvents can't be used on local variable
MyButton = New Button

Private Sub MyButton_Click(ByVal sender As System.Object, _
  ByVal e As System.EventArgs) Handles MyButton.Click 
  MessageBox.Show(Me, "Button was clicked", "Info", _
    MessageBoxButtons.OK, MessageBoxIcon.Information) 
End Sub
delegate void MsgArrivedEventHandler(string message);

event MsgArrivedEventHandler MsgArrivedEvent;







// Delegates must be used with events in C#


MsgArrivedEvent += new MsgArrivedEventHandler(My_MsgArrivedEventCallback);
MsgArrivedEvent("Test message");    // Throws exception if obj is null
MsgArrivedEvent -= new MsgArrivedEventHandler(My_MsgArrivedEventCallback);



using System.Windows.Forms;

Button MyButton = new Button(); 
MyButton.Click += new System.EventHandler(MyButton_Click);

private void MyButton_Click(object sender, System.EventArgs e) 
{ 
  MessageBox.Show(this, "Button was clicked", "Info", 
    MessageBoxButtons.OK, MessageBoxIcon.Information); 
}
      $set sourceformat(free) preservecase
      $set ilusing"System"
delegate-id. MsgArrivedEventHandler.
procedure division using by value messag as string.
end delegate MsgArrivedEventHandler.

class-id. a.
static.
01 MsgArrivedEvent type "MsgArrivedEventHandler" event.

*> Delegates must be used with events in COBOL
  method-id. main.
      set MsgArrivedEvent to type "Delegate"::"Combine"
      (
        MsgArrivedEvent,
        new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback")
      ) as type "MsgArrivedEventHandler"
      
      invoke MsgArrivedEvent::"Invoke"("Test message")    *> Throws exception if obj is null
      
      set MsgArrivedEvent to type "Delegate"::"Remove"
      ( 
        MsgArrivedEvent,
        new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback")
      ) as type "MsgArrivedEventHandler"
      
      invoke self::"add_MsgArrivedEvent"
       (new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback"))
      invoke MsgArrivedEvent::"Invoke"("Test message 2")
  end method main.
  method-id. My_MsgArrivedEventCallback.
  procedure division using by value str as string.
      display str
  end method My_MsgArrivedEventCallback.
end static.
end class a.

See demo program

Enumb.cbl

      $set sourceformat(free) preservecase
 enum-id. Action.
    78 #Start.   *> Start is a reserved word
    78 #Stop.
    78 #Rewind.
    78 #Forward.
 end enum Action.
 enum-id. Stat as "Status".
    78 Flunk value 50.
    78 Pass value 70.
    78 Excel value 90.
 end enum Stat.
 program-id. main.
    display type "Status"::"Pass" as binary-long *> prints 70
    display type "Status"::"Pass" *> prints Pass
 end program main.
Return To Table

Choices.cbl

      $set sourceformat(free)
program-id. a.
01 age binary-long.
01 greeting string.                    
01 x binary-long.
01 y binary-long.
01 color string value "blue".
01 r binary-long value 0.                     
01 b binary-long value 0.                     
01 g binary-long value 0. 
01 other-color binary-long value 0.
if age < 20
    move "What's up?" to greeting
else
    move "Hello" to greeting
end-if

if x not = 100 and y < 5
    multiply 5 by x
    multiply 2 by y
end-if

evaluate x
when > 5
    multiply y by x
when 5
    add y to x
when < 10
    subtract y from x
when other
    divide y into x
end-evaluate

evaluate color   *> can be any type
when "pink"
when "red"
    add 1 to r
when "blue"
    add 1 to b
when "green"
    add 1 to g
when other
    add 1 to other-color
end-evaluate
Return To Table

Loops.cbl

      $set sourceformat(free)
01 c binary-long value 0.
01 names string occurs any.
01 s string.
01 i binary-long value 0.
*>Pre-test loops:
perform until c >= 10   *> No WHILE keyword
    add 1 to c
end-perform
  
perform varying c from 2 by 2 until c > 10
    display c
end-perform

*> Post-test loops:
perform with test after until c >= 10
    add 1 to c
end-perform

*>Array or collection looping
set content of names to ("Fred" "Sue" "Barney")
perform varying s through names
    display s
end-perform

*>Breaking out of loops:
perform until false
    if i = 5
        exit perform
    end-if
    display i
    add 1 to i
end-perform

*>Continue to next iteration:
perform varying i from 0 by 1 until i >= 5
    if i < 4
        exit perform cycle
    end-if
    display i
end-perform
Return To Table

Arrays.cbl

      $set sourceformat(free)
      $set ilusing"System"
01 nums binary-long occurs any values 1, 2, 3.
01 names string occurs 5.    *> 5 is the size of the array
*> Can also do:
*>01 names string occurs any.
01 names2 string occurs 7.
01 twoD float-short occurs any, any.
01 jagged binary-long occurs any, occurs any.
01 rows binary-long value 3.
01 cols binary-long value 10.
       
set content of nums to (1 2 3 4)  *> Resets the contents of the array (optionally chaning the size

set size of names to 5   *> Create an array lf length 5
set names(1) to "David"  *> first element indexed as 1
*>set names(6) to "Bobby"  *> throws System.IndexOutOfRangeException

*> COBOL cannot directly resize an array - use copy
invoke type "Array"::"Copy"(names, names2, names::"Length")
*> or else:
invoke names::"CopyTo"(names2, 0)

set size of twoD to rows, cols

set size of jagged to 3
set size of jagged(1) to 5
set jagged(1 5) to 5
Return To Table

Functions-a.cbl

      $set sourceformat(free) preservecase
class-id. a.
static.       
method-id. main.
01 a binary-long value 1.
01 b binary-long value 1.
01 c binary-long.  *> c doesn't need initializing
01 total binary-long.
invoke self::"TestFunc"(a b c) *> or invoke self::"TestFunc"(value a reference b output c)
display a space b space c

set total to function sum(4 3 2 1) *> returns 10
invoke self::"SayHello"("Robert" "Mr.")
invoke self::"SayHello"("Robert")
end method main.       
method-id. TestFunc.
procedure division using by value x as binary-long, by reference y as binary-long, output z as binary-long.
add 1 to x, y
move 5 to z
end method TestFunc.
       
*> COBOL doesn't support optional arguments/parameters.  
*> Just create two different versions of the same function. 
method-id. SayHello.
procedure division using by value nam as string, prefix as string.
display "Greetings, " prefix space nam
                                        end method SayHello.
method-id. SayHello.
procedure division using by value nam as string.
invoke self::"SayHello"(nam "")
end method SayHello.
end static.
end class a.
 
Return To Table

Functions-b.cbl

      $set sourceformat(free) preservecase
class-id. a.
static.
method-id. main.
01 i binary-long.
    set i to self::"MySum"(1 2 3 4)
    display i
end method main.
Method-id. MySum.
01 i binary-long.
Procedure division using params nums as binary-long occurs any
                      returning mysum as binary-long.
    Perform varying i through nums
        Add i to mysum
    End-perform
    Goback
End method MySum.
end static.
end class a.
Return To Table

Strings.cbl

      $set sourceformat(free)
      $set ilusing"System"
*> x"0d"  *> carriage-return
*> x"0a"  *> line-feed
*> x"09"  *> tab
*> "\"    *> backslash
*> ""     *> quote

*> Chars
01 letter character.
01 word character occurs any.
01 school string value "Harding" & x"09".
*> String literal
01 msg string value "File is c:\temp\x.dat".
01 mascot string value "Bisons".
01 names string value "Frank,Becky,Ethan,Braden".
01 parts string occurs any.
01 dt type "DateTime" value new "DateTime"(1973, 10, 12).
01 s string.
01 x binary-long.
01 buffer type "System.Text.StringBuilder" value new "System.Text.StringBuilder"("two ").

*> string concatenation
    set school to string::"Concat"(school, "University")  *> school is "Harding (tab) University"
    set letter to school::"Chars"(0)   *> letter is H
    set letter to type "Convert"::"ToChar"(65) *> letter is A
    set letter to 65 as character      *> same thing
    set word to school::"ToCharArray"  *>word holds Harding


*>String comparison
    if mascot = "Bisons"    *> true
        display "Pass"
    end-if
    if mascot::"Equals"("Bisons")  *> true
        display "Pass"
    end-if
    if mascot::"ToUpper"::"Equals"("BISONS")  *> true
        display "Pass"
    end-if
    if mascot::"CompareTo"("Bisons") = 0  *> true
        display "Pass"
    end-if

*> String matching - no Like equivalent , use Regex

*> Substring
    set s to mascot::"Substring"(2 3) *> s is "son"

*> Replacement
    set s to mascot::"Replace"("sons" "nomial")  *> s is "Binomial"
    display s

*> Split
    set parts to names::"Split"(",")

*> Date to string
    set s to dt::"ToString"("MMM dd, yyyy")  *> Oct 12, 1973
    display s

*> string to int
    set x to type "Convert"::"ToInt32"("-5")   *> x is -5

*> Mutable string
    invoke buffer::"Append"("three ")
    invoke buffer::"Insert"(0, "one ")
    invoke buffer::"Replace"("two" "TWO")
    display buffer   *> Prints "one TWO three"

Return To Table

Exceptions.cbl

      $set sourceformat(free)
$set ilusing "System"
$set ilref"Microsoft.VisualBasic.dll"
*> Throw an exception
01 exc type "Exception"value new "Exception"("Something is really wrong.").
01 x binary-long.
01 y binary-long.

*> Catch an exception
try
  set y to 0;
  divide y into x
catch  exc   *> Argument is optional, no "When" keyword 
  display exc::"Message"
finally
  invoke type "Microsoft.VisualBasic.Interaction"::"Beep"
end-try

raise exc  *> ha ha
Return To Table

ClassesInterfaces.cbl

      $set sourceformat(free) preservecase
*> Inheritance
class-id. FootballGame inherits type "Competition".
end class FootballGame.


*> Interface definition
*>interface-id. IAlarmClock.
*>end interface IAlarmClock.

*> Extending an interface 
interface-id. IAlarmClock inherits type "IClock".
end interface IAlarmClock.


*> Interface implementation
class-id. WristWatch implements type "IAlarmClock", type "ITimer".
end class WristWatch.

interface-id. IClock.
end interface IClock.
interface-id. ITimer.
end interface ITimer.
class-id. Competition.
end class Competition.
Return To Table

ConstructorsDestructors.cbl

      $set sourceformat(free) preservecase
class-id. SuperHero.
01 _powerLevel binary-long.

method-id. new.
procedure division.
    set _powerLevel to 0
end method new.

method-id. new.
procedure division using by value powerLevel as binary-long.
    set _powerLevel to powerLevel
end method new.

method-id. Finalize override protected.
    *> Destructor code to free unmanaged resources.
    *> Implicitly creates a Finalize method
end method Finalize.
end class SuperHero.
Return To Table

UsingObjects.cbl

      $set sourceformat(free) preservecase
      $set ilusing"System.IO"
program-id. main.
01 hero type "SuperHero" value new "SuperHero".
01 hero2 type "SuperHero".
01 obj object.
01 reader type "StreamReader".
01 lin string.

// No "With" construct
set hero::"Name" to "SpamMan"
set hero::"PowerLevel" to 3


invoke hero::"Defend"("Laura Jones")
invoke type "SuperHero"::"Rest"   *> Calling static method



set hero2 to hero      *> Both reference the same object
set hero2::"Name" to "WormWoman"
display hero::"Name"   *> Prints WormWoman

set hero to null       *> Free the object

if hero = null
    set hero to new "SuperHero"
end-if

set obj to new "SuperHero"
if obj is instance of type "SuperHero"
    display "Is a SuperHero object."
end-if

*> No 'using' construct in COBOL
try
    set reader to type "File"::"OpenText"("test.txt")
    perform until exit
        set lin to reader::"ReadLine"
        if lin = null
            exit perform
        end-if
    end-perform
finally
    if reader not = null
        invoke reader::"Dispose"
    end-if
end-try
end program main.

class-id. SuperHero.
static.
method-id. Rest.
end method Rest.
end static.
object.
01 #Name string property.
01 PowerLevel binary-long property.
method-id. Defend.
procedure division using by value attacker as string.
end method Defend.
end object.
end class SuperHero.
Return To Table

Structs.cbl

      $set sourceformat(free) preservecase
valuetype-id. StudentRecord.
object.
01 #name string public.
01 gpa float-short public.
method-id. new.
procedure division using by value nam as string, gpa as float-short.
    set #name to nam
    set self::"gpa" to gpa
end method new.
end object.
end valuetype StudentRecord.

class-id. a.
static.
method-id. main.
01 stu type "StudentRecord" value new "StudentRecord"("Bob", 3.5).
01 stu2 type "StudentRecord".
procedure division.
    set stu2 to stu
    set stu2::"name" to "Sue"
    display stu::"name"   *> Prints Bob
    display stu2::"name"  *> Prints Sue
end method main.
end static.
end class a.
Return To Table

Properties.cbl

      $set sourceformat(free) preservecase
class-id. MyClass.
object.
01 _size binary-long private.
method-id. get property #Size.
procedure division returning ret as binary-long.
    set ret to _size
end method.
method-id. set property #Size.
procedure division using by value val as binary-long.
    if val < 0
        set _size to 0
    else
        set _size to val
    end-if
end method.
end object.
end class MyClass.

class-id. a.
static.
method-id. main.
01 foo type "MyClass" value new"MyClass".
    add 1 to foo::"Size"
    display foo::"Size"
end method main.
end static.
end class a.
Return To Table

DelegatesEvents.cbl

      $set sourceformat(free) preservecase
      $set ilusing"System"
delegate-id. MsgArrivedEventHandler.
procedure division using by value messag as string.
end delegate MsgArrivedEventHandler.

class-id. a.
static.
01 MsgArrivedEvent type "MsgArrivedEventHandler" event.

*> Delegates must be used with events in C#
  method-id. main.
      set MsgArrivedEvent to type "Delegate"::"Combine"(MsgArrivedEvent,
                                      new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback")) as type "MsgArrivedEventHandler"
      invoke MsgArrivedEvent::"Invoke"("Test message")    *> Throws exception if obj is null
      set MsgArrivedEvent to type "Delegate"::"Remove"(MsgArrivedEvent,
                                      new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback")) as type "MsgArrivedEventHandler"
      invoke self::"add_MsgArrivedEvent"(new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback"))
      invoke MsgArrivedEvent::"Invoke"("Test message 2")    *> Throws exception if obj is null
  end method main.
  method-id. My_MsgArrivedEventCallback.
  procedure division using by value str as string.
      display str
  end method My_MsgArrivedEventCallback.
end static.
end class a.
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This document quotes heavily from the following (with thanks): Produced by Dr. Frank McCown, Harding University Computer Science Dept Additional COBOL information was created by Robert Sales, Micro Focus International merging and reformatted was by Alex Turner, Micro Focus International This work is licensed under a Creative Commons

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About the Author

alex turner
Web Developer
United Kingdom United Kingdom
I am now a Software Systems Developer - Senior Principal at Micro Focus Plc. I am honoured to work in a team developing new compiler and runtime technology for Micro Focus.
 
My past includes a Ph.D. in computational quantum mechanics, software consultancy and several/various software development and architecture positions.
 
For more - see
 
blog: http://nerds-central.blogspot.com
 
twitter: http://twitter.com/alexturner

Comments and Discussions

 
GeneralMy vote of 5 PinmemberMlsoun16-Jan-11 11:59 
_
QuestionDelegates example Pinmemberdmccollim5-Mar-10 7:16 
AnswerRe: Delegates example Pinmemberalex turner5-Mar-10 8:07 
GeneralInteresting PinmemberRugbyLeague3-Mar-10 23:26 
GeneralNice Pinmemberbosl14-Jan-10 4:52 
GeneralRe: Nice Pinmemberalex turner14-Jan-10 4:57 
GeneralRe: Nice Pinmemberalex turner14-Jan-10 5:10 
GeneralRe: Nice Pinmemberbosl14-Jan-10 8:29 
GeneralMy vote of 1 Pinmemberbabakzawari19-Dec-09 3:57 
GeneralRe: My vote of 1 Pinmemberalex turner20-Dec-09 22:53 
GeneralRe: My vote of 1 PinmvpPaul Conrad25-Dec-09 12:01 
GeneralRe: My vote of 1 Pinmemberalex turner27-Dec-09 0:39 
GeneralRe: My vote of 5 PinmvpPaul Conrad27-Dec-09 6:10 
GeneralRe: My vote of 5 Pinmemberalex turner29-Dec-09 0:48 
QuestionAcuCOBOL? Pinmemberdave vorgang16-Dec-09 7:15 
AnswerRe: AcuCOBOL? Pinmemberalex turner16-Dec-09 7:33 
GeneralRe: AcuCOBOL? Pinmemberdave vorgang16-Dec-09 7:38 
GeneralRe: AcuCOBOL? Pinmemberdave vorgang16-Dec-09 7:40 
GeneralRe: AcuCOBOL? Pinmemberalex turner16-Dec-09 9:34 
GeneralRe: AcuCOBOL? Pinmemberalex turner16-Dec-09 7:40 
GeneralWell done! Pinmembermburgun16-Dec-09 0:28 
GeneralRe: Well done! Pinmemberalex turner16-Dec-09 0:32 
GeneralRe: Well done! Pinmemberalex turner23-Dec-09 2:12 
QuestionWhy? Pinmembergeorani15-Dec-09 12:23 
AnswerRe: Why? Pinmemberalex turner15-Dec-09 22:38 

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