Question

I’m trying to brush up on my LINQ by writing some simple extension methods. Is there any better way to write such a function as below that removes a given list of characters from a string (using LINQ)?

It helps me to think of the extension methods that LINQ relies on first:

public static string Remove(this string s, IEnumerable<char> chars) {     string removeChars = string.Concat(chars);      return new string(s.ToCharArray().Where(c => !removeChars.Contains(c)).ToArray()); } 

But that’s pretty ugly. Ergo LINQ.

The difference that I notice in the LINQ statement is that I have to use ‘select’ whereas with the extension method, I don’t have to.

/// <summary>Strip characters out of a string.</summary> /// <param name='chars'>The characters to remove.</param> public static string Remove(this string s, IEnumerable<char> chars) {     string removeChars = string.Concat(chars);      var stripped = from c in s.ToCharArray()                    where !removeChars.Contains(c)                    select c;      return new string(stripped.ToArray()); } 

So I’m wondering if this (last snippet above) is the tersest LINQ statement to accomplish removal of characters.

Answer 1

I would prefer the first form with extension methods though simplified to

public static string Remove(this string s, IEnumerable<char> chars) {     return new string(s.Where(c => !chars.Contains(c)).ToArray()); } 

As for select keyword, it’s obligatory in second form. The documentation says what ‘A query expression must terminate with either a select clause or a group clause’. That’s why I would avoid LINQ syntactic sugar.