Deleting a window property in IE

Question

I can\'t find any information on this issue; why doesn\'t the following code work in IE?

window.x = 45;
delete window.x;
// or delete window[\'x\'];

Answer 1

I implemented this solution when dealing with caching my own data - the data wasn't much the the frequency of the cache was such that the memory leak might have become an issue. It's costly, but periodically remapping the object was the easiest way for me to be sure it wasn't getting out of hand.

obj = {a: 1, b: 2, c: 3};
var max;

function unset(obj, key) {
    try {
        delete obj[key];
    } catch (e) {
        obj[key] = undefined;
    }

    max++;

    if(max > 200) {
        var keys = Object.keys(obj);
        var len = keys.length;
        var n_obj = {};
        for(var i = 0; i < len; i++) {
            if(obj.hasOwnProperty(keys[i]) && obj[keys[i]] !== undefined) {
                n_obj[keys[i]] = obj[keys[i]];
            }
        }
        return n_obj;
    }
    return obj;
}

obj; //{a: 1, b: 2, c: 3}
obj = unset(obj, "b"); //{a: 1, b: undefined, c: 3} OR {a: 1, c: 3}
//and then eventually we'll garbage collect and...
obj = unset(obj, "b"); //{a: 1, c: 3}   

Hopefully, that's useful to some!