extend js String to implement basic trim methods

js-string-ext-trim.js

function strltrim() {
  return this.replace(/^\s+/,'');
}

function strrtrim() {
  return this.replace(/\s+$/,'');
}

function strtrim() {
  return this.replace(/^\s+/,'').replace(/\s+$/,'');
}

String.prototype.ltrim = strltrim;
String.prototype.rtrim = strrtrim;
String.prototype.trim = strtrim;

var name = "  middle ";

console.log("a" + name.trim() + "z");  // amiddlez
console.log("a" + name.rtrim() + "z"); // a  middlez
console.log("a" + name.ltrim() + "z"); // amiddle z