JSFiddle - React, Tailwind, and code Playground

by Jessie Lau

JavaScript

function maskify(cc) {
    var lastFour = cc.slice(-4);
    var res = "";
    for (var i = 0; i < cc.length - 4; i++) {
        res += "#";
    }
    return res + lastFour;
}
console.log(maskify('4556364607935616'));