What does "return true" do in this part of code?


#1

Hi all. I want to know what does "return true" do in the following object prototype code? It's after the scan method. Thanks.

var cashRegister = {
    total:0,
    //Dont forget to add your property
    lastTransactionAmount: 0,
    add: function(itemCost) {
        this.total +=  itemCost;
        this.lastTransactionAmount = 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
console.log('Your bill is '+cashRegister.total);

#2

Raise this question a lot, for one.

It gives a defined return value to the caller, for another.

What purpose it serves in the present construct is a bit of a mystery due to missing support logic. We could add a line that would give meaning to this,

default: return false;

At least this way the function is returning one or the other boolean. But how do we use this infomation?


#3

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.