Multiple condition in C# in if condition

Question

5.00/5 (1 vote)

See more:

i am new comer in c#. before i am using oracle .
Any easier way to write this if statement?

if (value==1 || value==2)

For example... in SQL you can say where value in (1,2) instead of where value=1 or value=2.
i want to try to call procedure based on string contains particular value for eg
p_value.startwith("414","413")
ie p_value is 41400 or 41300 or 41402 etc

please help me

What I have tried:

i have tried
value.contains ("414","412")
{
some code;
}
or value.startwith("414","412")
{\some code

Posted 16-Oct-16 18:31pm

forest4ever

Updated 17-Oct-16 3:38am

v2

Add a Solution

Comments

PIEBALDconsult 17-Oct-16 0:55am

I'd use a HashSet.

Philippe Mori 17-Oct-16 9:09am

If I have only 2 conditions and don't expect that to change in future, I would stay with your original code which is still the easiest to understand and the more efficient.

4 solutions

Solution 1

You can use something like below

C#

using System.Linq;

public static bool CheckIn<T>(this T item, params T[] Mylist)
{
    return list.Contains(item);
}


var list = new List<int> { 1, 2, 3, 4, 5 };

if (!list .CheckIn(1,3,4))

Posted 16-Oct-16 18:45pm

Kamal Mahendra Sirisena

Comments

forest4ever 17-Oct-16 0:56am

sorry sir, it cannot work in my program . i want to check 3 strings in code
if substring(act_valve,1,3) in ("414","412","410")
{
generete_code()
} else
generate_para()
}
please help me

Solution 3

Here's an extension method I wrote for myself:

C#

public static bool IsIn(this string str, string container, bool exact=true)
{
    bool result = !string.IsNullOrEmpty(str);
    if (result)
    {
        result = (exact) ? (str          == container)          || container.IndexOf(str) >= 0
                         : str.ToUpper() == container.ToUpper() || container.ToUpper().IndexOf(str.ToUpper()) >= 0;
    }
    return result;
}

Usage would be something like this:

C#

string badStuff = "Text,we,don't,want";
string ourData = "text";

bool thisIsFalse = ourData.IsIn(badStuff); // because "text" is lowercase and 
                                           // exact is true

bool thisIsTrue  = ourData.IsIn(badStuff, false); // because exact is false, so 
                                                  // case sensitivity is irrelevant

This idea can be carried into overloads of this method with IEnumerable<string>, or even IEnumerabe<YourObject>, string propertyname as parameters.

You could even do it with other types:

C#

public static bool IsIn(int this value, string container)
{
    return value.ToString().IsIn(container);
}

Posted 17-Oct-16 1:24am

#realJSOP

Updated 17-Oct-16 1:32am

v3

Solution 4

Here are some extension methods that let you overload the method I posted earlier.

C#

public static bool IsIn(this string str, IEnumerable<string> list, bool caseSensitive = true)
{
    return (caseSensitive) ? (list.Where(x=>x==str).FirstOrDefault() != null) 
                            : (list.Where(x=>x.ToUpper() == str.ToUpper()).FirstOrDefault() != null);
}

public static bool IsIn<T>(this string str, IEnumerable<T> list, string propertyName, bool caseSensitive = true)
{
    Type itemType = typeof(T);
    PropertyInfo info = itemType.GetPropertyInfo(propertyName, TypeChecker.String);
    if (info == null)
    {
        throw new InvalidOperationException(string.Format("Named property ({0}) is not a string.", propertyName));
    }
    return (caseSensitive) ? (list.Where(x=>info.GetValue(x).ToString()==str).FirstOrDefault() != null) 
                            : (list.Where(x=>info.GetValue(x).ToString().ToUpper() == str.ToUpper()).FirstOrDefault() != null);
}

Posted 17-Oct-16 3:38am

#realJSOP

Updated 17-Oct-16 3:39am

v2

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Midi_Mick · Accepted Answer · 2016-10-16T23:35:00

Solution 2

The Linq extensions have two handy boolean methods - All and Any. These could be used for your situation thus:

C#

if (new[]{"414", "412", "410"}.Any(s=>value.StartsWith(s))) {
   // Do your stuff
}

Posted 16-Oct-16 23:35pm

Midi_Mick

Updated 16-Oct-16 23:37pm

v2