Question

While trying to port and generally playing around with some non-browser code, I came across getters and setters that looked like normal object properties. Something like this:

js> var o = {
    a: 4,
    get b(){
        return this.a + 3;
    },
    set b(val){
        this.a = val - 3;
    }
};
js> o.a
4
js> o.b
7
js> o.b=10
10
js> o.a
7

This seems to work in recent versions of Rhino and Spidermonkey, but is it possible to implement or simulate the behavior (the defining syntax is less important to me) in JScript (Windows Script Host)?

Answer 1

The answer is No. Setters and getters are just properties that act like functions, but there is no way to emulate the syntax correctly. I had a half-way concept of emulating getters and setters on HTML elements in <=IE7 using behaviors, but even that turned out to be more difficult than I first imagined it would. Even IE8 only supports getters/setters on DOM objects and not JScript objects, so I think it s something the JScript team need to include, if they ever do.

If only someone had thought to include setters and getters in the original JScript/ECMAScript implementations.

Answer 2

According to this article (by John Resig, creator of jQuery), Javascript getters and setters are supported in JScript.NET 8.

Answer 3

This si a complete list of browsers and their support for getters and setters. http://robertnyman.com/javascript/#javascript-getters-setters-object-defineproperty-compatibility

友情链接