Javascript String replacer(replaceObject)

String.prototype.replacer = function(replaceObject) {
    let replaceString = this;
    let regex;/*from   ww  w .j  a  v  a 2  s . c  o m*/
    for(let key in replaceObject) {
        regex = new RegExp(key, "g");
        replaceString = replaceString.replace(regex, replaceObject[key]);
    }
    return replaceString;
};