ucwords in JavaScript - Equivalent to PHP's ucwords() Returns a string with the first letter in upper case of each word.

ucwords.js

String.prototype.ucwords = function() {
  str = this.toLowerCase();
  return str.replace(/(^([a-zA-Z\p{M}]))|([ -][a-zA-Z\p{M}])/g,
  	function(s){
  	  return s.toUpperCase();
	});
};

I use str.toLowerCase().replace(/(?<= )[^\s]|^./g, a=>a.toUpperCase())

Thanks, this worked.

I use str.toLowerCase().replace(/(?<= )[^\s]|^./g, a=>a.toUpperCase())

Thanks, this worked.

Careful though, that last one doesn't work in Safari. For some reason, it doesn't support lookbehind regex.
So I am now using (' '+str).replace(/ [\w]/g, a => a.toLocaleUpperCase()).trim(); ...