Reg Exp

ugenn · 09-19-2002, 10:10 AM

what is the regular exp to match a string consisting only of
white spaces?

Ztyx · 09-19-2002, 10:26 AM

Is there really a regular expression for that?
In what language are you programming in?

ugenn · 09-19-2002, 11:04 AM

Quote:

Originally posted by ugenn
what is the regular exp to match a string consisting only of
white spaces?

Javascript. Does it really matter what language I'm using?
Aren't regex syntax the same?

neo77777 · 09-19-2002, 11:22 AM

For instance, in perl regex processing supports \s to be used to match a whitespace, I really haven't used anything but perl for pattern matching and other text manipulations, so in perl it would look like
\s+
meaning to match exactly one or more consecutive whitespaces

TheLinuxDuck · 09-19-2002, 12:01 PM

It should be the same, regardless of the language.. however, according to http://www.webreference.com/js/column5/ javascript's regexp's were created based on perl's regexp.

neo is right that \s will match whitespace.. the only thing missing is the fact that you asked for a regexp that would match a string that consists ONLY of whitespace, which means that the start/end line boundary's will need to be used. I'm not super familar with javascript, but here is my attempt:

Code:

function isWhiteSpacel(myString)_
{
  var inString = myString.match(/^\s*$/);
  if (inString) {
    alert("string '"+ myString + "' contains only whitespace")
  }
}

Note that I used * instead of +, as neo suggested... this + means one or more, and * means zero or more, so this version will match even a blank string. I use something similar when parsing config files in perl.