So I’ve been doing a LOT of Javascript programming in the last few days and I ran into a few limitations of the language or constructs within the language. For example, certain versions of IE do not support the Array.indexOf() method. Another problem I ran into is that the Javascript language does not contain a method for performing deep copies on objects. So after some Googling I found a few ways around the aforementioned problems. The first one (indexOf) is as follows:

Array.prototype.findObject = (
    !Array.indexOf ? function (o) {
        var l = this.length + 1;
        while (l–) {
            if (this[l - 1] === o) return l – 1;
        }
        return -1;
    } : function (o) { return (this.indexOf(o) !== -1); }
);

The above code will add the ‘findObject’ method to your Array objects. Then you can use that instead of indexOf() and be guaranteed that it will work regardless if the browser supports indexOf or not.

The second one (deep copying) can be circumvented by creating a helper method which will perform the copy for you:

var ObjectHandler = {
    //public method
    getCloneOfObject: function(oldObject) {
        var tempClone = {};

        if (typeof(oldObject) == "object")
            for (prop in oldObject)
                // for array use private method getCloneOfArray
                if ((typeof(oldObject[prop]) == "object") &&
                                (oldObject[prop]).__isArray)
                    tempClone[prop] = this.getCloneOfArray(oldObject[prop]);
                // for object make recursive call to getCloneOfObject
                else if (typeof(oldObject[prop]) == "object")
                    tempClone[prop] = this.getCloneOfObject(oldObject[prop]);
                // normal (non-object type) members
                else
                    tempClone[prop] = oldObject[prop];

        return tempClone;
    },

    //private method (to copy array of objects) – getCloneOfObject will use this internally
    getCloneOfArray: function(oldArray) {
        var tempClone = [];

        for (var arrIndex = 0; arrIndex <= oldArray.length; arrIndex++)
            if (typeof(oldArray[arrIndex]) == "object")
                tempClone.push(this.getCloneOfObject(oldArray[arrIndex]));
            else
                tempClone.push(oldArray[arrIndex]);

        return tempClone;
    }
};

Just thought I’d share those with everyone. Credit for the majority of the deep copy code goes to http://blog.pramatiservices.com/deep-copy-in-javascript/ and credit for the findObject code goes to someone other than me, but I didn’t bookmark the link so I can’t find it again. Sorry :(