The trim() methods in JavaScript removes spaces and other whitespace characters from both ends of a string. It is supported in all modern browsers and you can add the trim() method to the String prototype object for supporting older browser versions.

The \s represent whitespace characters while \uFEFF represents the zero-width no-break space.

''.trim ||
  (String.prototype.trim = function () {
    return this.replace(/^[\s\uFEFF]+|[\s\uFEFF]+$/g, '');
  });