Question

Super simple abstracted example, but I’m wondering if there is a way I can invoke updateAge() from within doMainStuff to update the person object’s age property? Is this where call() or apply() come into play?

function doMainStuff() {
    var person = {
        name: 'Bob',
        age: 55
    }

    updateAge();
}


function updateAge(){
    person.age = 24;
}

Answer 1

You’ll have to pass the person object to your updateAge function:

function doMainStuff () {
    var person = {
        name: 'Bob',
        age: 55
    };

    updateAge(person);
}


function updateAge (person) {
    person.age = 24;
}