Question

Lets say I have a Javascript object:

var myObj = {
 property1 : 20,
 property2 : -20
}

But instead of -20 for property2, I need to take the value of property1 and convert it to its negative within property2:

var myObj = {
 property1 : 20,
 property2 : this.property1 * -1
}

This doesn’t work, but I think it illustrates what I want to accomplish.

Answer 1

I could suggest you the following

var myObj = {
    property1 : 20,
    get_property2 : function() {
        return this.property1 * -1;
    },
    set_property2 : function(value) {
        this.property1 = value * -1;
    }
}

Edit

Seems that this is a dependant property so it is readonly. But I’ve edited the code so that it is also writable.