javascript defineProperty to make an attribute non enumerable

constructor, defineproperty, ecmascript-5, javascript, object

Solution

`Item` does not have a property named `nonEnum` (check it out). It is a (constructor) function that will create an object that has a property called `nonEnum`.

So this one would work:

var test = new Item();
Object.defineProperty(test, "nonEnum", { enumerable: false });

You could also write this function like this:

function Item() {
    this.enumerable = "enum";
    Object.defineProperty(this, "nonEnum", { 
        enumerable: false, 
        value: 'noEnum' 
    });
}

jsFiddle Demo

Problem

I'm trying to use defineProperty to made attributes not appear in for...in cycle, but it doesn't work. Is this code correct? ``` function Item() { this.enumerable = "enum"; this.nonEnum = "noEnum"; } Object.defineProperty(Item, "nonEnum", { enumerable: false }); var test = new Item(); for (var tmp in test){ console.log(tmp); } ```

Original source