How can I determine if a string only contains spaces, using javascript?

Question

How can I determine if an input string only contains spaces, using javascript?

Answer 1

Another good post for : Faster JavaScript Trim

You just need to apply trim function and check the length of the string. If the length after trimming is 0 - then the string contains only spaces.

var str = "data abc";
if((jQuery.trim( str )).length==0)
  alert("only spaces");
else 
  alert("contains other characters");

Answer 2

The fastest solution is using the regex prototype function test() and looking for any character that is not a space or a line break \S :

if (/\S/.test(str))
{
    // found something other than a space or a line break
}

In case that you have a super long string, it can make a significant difference.

Answer 3

if(!input.match(/^([\s\t\r\n]*)$/)) {
    blah.blah();
} 

Answer 4

Alternatively, you can do a test() which returns a boolean instead of an array

//assuming input is the string to test
if(/^\s*$/.test(input)){
    //has spaces
}

Answer 5

if (!input.match(/^\s*$/)) {
    //your turn...
}