Question

How can I remove all white space from the beginning and end of a string?

Like so:

"hello" returns "hello"
"hello " returns "hello"
" hello " returns "hello"
" hello world " returns "hello world"

Answer 1

String.Trim() returns a string which equals the input string with all white-spaces trimmed from start and end:

"   A String   ".Trim() -> "A String"

String.TrimStart() returns a string with white-spaces trimmed from the start:

"   A String   ".TrimStart() -> "A String   "

String.TrimEnd() returns a string with white-spaces trimmed from the end:

"   A String   ".TrimEnd() -> "   A String"

None of the methods modify the original string object.

(In some implementations at least, if there are no white-spaces to be trimmed, you get back the same string object you started with:

csharp> string a = "a";
csharp> string trimmed = a.Trim();
csharp> (object) a == (object) trimmed;
returns true

I don’t know whether this is guaranteed by the language.)