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);
}

Answer 2

//                      ^ start string 
//                      || \s+ white space one or more times 
//                      || || $ = end string                        
//                      || || ||
//                      \/ \/ \/

const isAllWhiteSpace = /^\s+$/.test(myvalue)

Answer 3

Like this...

function isEmpty(str) {
  return str.replace(/^\s+|\s+$/g, '').length == 0;
}

Answer 4

This will also work:

var text = "   ";
text.trim().length == 0; //true

Answer 5

yo, we can check simply bt trim, as javascript is tagged in question,

console.log('     '.trim() === '')//check for all empty spaces

console.log('     '.trim() === '')//check for all empty tabs

console.log('\n \n'.trim() === '')//check for all empty enter(empty new line)

console.log('         \n'.trim() === '')//check for all spaces, tabs and new line

Answer 6

To find whitespace generated by JavaScript and between elements use:

var trimmed = $.trim( $('p').text() );

if ( trimmed === '' ){
    //function...
}