Question

I know how to do this using for loops. Is it possible to do something like this using LINQ or lambdas?

int[] a = { 10, 20, 30 }; int[] b = { 2, 4, 10 }; int[] c = a * b; //resulting array should be { 20, 80, 300 } 

Answer 1

EDIT: The code below will work, but it’s not as readable as using an explicit method. LINQ is great where it definitely adds to readability… but this isn’t one of those cases.

This is a briefer version of CMS’s answer – the extra let isn’t required, and when you’re just doing a projection it’s simpler to just use dot notation:

int[] result = Enumerable.Range(0, a.Length)                          .Select(i => a[i] * b[i])                          .ToArray(); 

An alternative is to use the form of Select which takes an index:

int[] result = a.Select((value, index) => value * b[index])                 .ToArray();