Convert a function from c# to Lambda

Question

0.00/5 (No votes)

See more:

Hello All,

I have written this function which is as follows:

C#

public static long ByteArrayToLong(byte[] input)
        {
            long accumulator=0;
            byte counter = 0;


            for (counter=0; counter<input.Length -1; counter++)
                accumulator += (input[counter] & 0xff) << (8 * counter);

            return accumulator;

        }

Could anybody tell me how I can do this in lambda please?

Many thanks in advance.

Posted 29-Mar-12 6:02am

Member1978

Updated 20-Jun-12 3:54am

v3

Add a Solution

1 solution

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)

Henning Dieterichs · Accepted Answer · 2012-03-29T06:10:00

Solution 1

C#

Func<byte[], long> f = (input) => 
{
  long accumulator=0;
  byte counter = 0;
 

  for (counter=0; counter<input.Length -1; counter++)
    accumulator += (input[counter] & 0xff) << (8 * counter);
 
  return accumulator;
}
long result = f(new byte[] {0,4,1});

Or:

C#

data.Select((value, index) => new KeyValuePair<int, byte>(index, value)).Sum(k => (k.Value & 0xff) << (8 * k.Key));

Posted 29-Mar-12 6:10am

Henning Dieterichs

Updated 29-Mar-12 6:18am

v3

Comments

Henning Dieterichs 29-Mar-12 12:19pm

See my update. Not very nice (as it is not really sense-full), but should work.

Henning Dieterichs 29-Mar-12 18:35pm

Maybe I am the best (yes, pride goes before a fall :) ), but my second solution is not...
This lambda expression is bad, as the intermediate step with "select" is an ugly hack (better: write your own sum-extension-method method which passes both index and value).

Lambda in C# is nothing more than "=>" which represents an anonymous function.
So my first solution is already a complete lambda expression.

What you wanted, is using the default LINQ (language integrated query) in connection with lambda, which is realized through extension-methods on IEnumerable<t>. For LINQ you have not to use lambda-expressions and for lambda-expressions you dont have to use LINQ.
As the most LINQ-extension-methods on IEnumerable<t> returns again IEnumerable<t> and take a Predicate (= Func<t, boolean=""> = delegate boolean (T element)) you can do some cool stuff.

If you want to learn lambda-expressions and LINQ, you should play around with them: define an array (e.g. int[]) and look what methods Intelli-Sense suggest you.

Greetings,
Henning