JSFiddle - React, Tailwind, and code Playground

by Eric Howe

JavaScript

Number.prototype.__defineSetter__('leftPad0',
    function(v) {
        alert('In setter: ' + v + ' ' + (this instanceof Number));
        var len = (String(v).length - String(this).length) + 1;
        this._leftPad0 = new Array(len).join('0') + this;
    }
);

var a = new Number(977);
a.leftPad0 = 10000;
alert('a => ' + a._leftPad0);

var b = 977;
b.leftPad0 = 10000;
alert('b => ' + b._leftPad0);