Javascript object deep copy

gistfile1.js

function processObjWithRef(obj, result){
    if(obj==null || typeof obj != 'object'){
        //nothing really to do here - you're going to lose the reference to result if you try an assignment
    }
    if(obj instanceof Array) {
        for(var i=0; i<obj.length; i++){
            result.push();
            processObjWithRef(obj[i], result[i]);
        }
    }    
    if(obj instanceof Object){
        for(var k in obj){
            var count=0;
            if(obj[k]==null || typeof obj[k] != 'object'){
                result[k] = obj[k];
            }else if(obj[k] instanceof Array) {
                result[k] = [];
                processObjWithRef(obj[k], result[k]);
            }else if(obj[k] instanceof Object){
                result[k] = {};
                for( var attr in obj[k]){
                    processObjWithRef(obj[k], result[k]);
                }
            }
        }
    }
}

What is line 13 suppose to be counting?

Probably our ability to detect a leftover variable. 😄 Should be using Array.isArray() to detect arrays, probably, and using "===" for comparison against null. The last loop would be a lot faster using function variables rather than if() tests, but one would have to use typeof instead of instanceof in order to make that work.

This fails while cloning a simple case: var b = { a: 10, b: { ba: new Date(), bb: [ 1, 2, { bba: 'pp' } ] } }; var c = {}; processObjWithRef( b, c );. Fails with TypeError: Cannot set property 'bba' of undefined