In JavaScript, what happens if I assign to an object property that has a getter but no setter?

Question

In the following code, both uses of console.log(ox) print 1 . What happens to the assignment ox = 2 ? Is it just ignored?

var o = {
    get x() {
        return 1;
    }
}

console.log(o.x);  // 1
o.x = 2
console.log(o.x);  // 1

Answer 1

In sloppy mode, yes, it'll just be ignored - the value "assigned" will be discarded. But in strict mode (which is recommended), the following error will be thrown:

Uncaught TypeError: Cannot set property x of #<Object> which has only a getter

 'use strict'; var o = { get x() { return 1; } } console.log(ox); // 1 ox = 2