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

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.