JSFiddle - React, Tailwind, and code Playground

by Alex Azuero

JavaScript

var cashRegister = {
    total:0,
    //Dont forget to add your property
    lastTransactionAmount: 0,
    add: function(itemCost) {
        this.lastTransactionAmount= itemCost;
        //alert( this.lastTransactionAmount);
        this.total +=  itemCost;
    },
    scan: function(item,quantity) {
        switch (item) {
        case "eggs": this.add(0.98 * quantity); break;
        case "milk": this.add(1.23 * quantity); break;
        case "magazine": this.add(4.99 * quantity); break;
        case "chocolate": this.add(0.45 * quantity); break;
        }
        return true;
    },
    //Add the voidLastTransaction Method here
    voidLastTransaction: function() {
        this.total -= this.lastTransactionAmount;
    }
    
};

cashRegister.scan('eggs',1);
cashRegister.scan('milk',1);
cashRegister.scan('magazine',1);
cashRegister.scan('chocolate',4);

//Void the last transaction and then add 3 instead

cashRegister.voidLastTransaction();

cashRegister.scan('chocolate',3);


//Show the total bill
alert('Your bill is '+cashRegister.total);