How to check if a text is all white space characters in client side?

Question

How to check if a user input text is all white space characters (space, tab, enter etc) in client side?

Answer 1

If you want to see if a file contains all white space or is empty, I would recommend testing the inversion and inverting the result. That way you don't need to worry about special cases around empty string.

all whitespace is the same as no non-whitespace so:

function isWhitespaceOrEmpty(text) {
   return !/[^\s]/.test(text);
}

If you don't want empty strings you can modify it slightly:

function isWhitespaceNotEmpty(text) {
   return text.length > 0 && !/[^\s]/.test(text);
}