.net - Removing White Space: C# -

i trying remove white space exists in string input. ultimate goal create infix evaluator, having issues parsing input expression.

it seems me easy solution using regular expression function, namely regex.replace(...)

here's have far..

infixexp = regex.replace(infixexp, "\\s+", string.empty); string[] substrings = regex.split(infixexp, "(\\()|(\\))|(-)|(\\+)|(\\*)|(/)"); 

assuming user inputs infix expression (2 + 3) * 4, expect break string array {(, 2, +, 3, ), *, 4}; however, after debugging, getting following output:

infixexp = "(2+3)*7" substrings = {"", (, 2, +, 3, ), "", *, 7} 

it appears white space being removed infix expression, splitting resulting string improper.

could give me insight why? likewise, if have constructive criticism or suggestions, let me know!

if match @ 1 end of string, empty match next it. likewise, if there 2 adjacent matches, string split on both of them, end empty string in between. citing msdn:

if multiple matches adjacent 1 another, empty string inserted array. example, splitting string on single hyphen causes returned array include empty string in position 2 adjacent hyphens found [...].

and

if match found @ beginning or end of input string, empty string included @ beginning or end of returned array.

just filter them out in second step.

also, please make life easier , use verbatim strings:

infixexp = regex.replace(infixexp, @"\s+", string.empty); string[] substrings = regex.split(infixexp, @"(\(|\)|-|\+|\*|/)"); 

the second expression simplified further:

@"([()+*/-])"