var myString = "He is such an ahole. I can't believe how much of a jackass he can be!"; var updateMyString = myString.replace(/ahole|jackass/g, function (s) { var i = 0; var hashs = ""; while (i < s.length) { hashs += "*"; i++; } return hashs; }); console.log(updateMyString); /*logs He is such an *****. I can't believe how much of a ******* he can be! */