JSFiddle - React, Tailwind, and code Playground

by Neels Grobler

JavaScript

var extendedArray = function() {
    var arr = [];
    arr.push.apply(arr, arguments);
    
    arr.clearArray = function() {
        this.oldValue = this.slice(0);
        this.length = 0;
    }
    
    arr.undoArray = function() {
        this.length = 0;
        for (var i = 0; i < this.oldValue.length; i++) {
            this.push(this.oldValue[i]);
        }
    }
    return arr;
};

var a = extendedArray('f', 'o', 'o');

alert(a);
a.clearArray();
alert(a);
a.undoArray();
alert(a);