javascript merge two arrays/objects

I just want to simulate PHP's array_merge function in javascript.

So how to merge two normal arrays in javascript? The answer is Array.concat method. Check this code:

var o1 = [1, 2], o2 = ['a','b'];

//we will have an array [1,2,'a','b']

console.log(o1.concat(o2));

How about objects? Javascript object is actually the concept of associative array in PHP:

var o1 = {category:'living', name:'unknown'};

var o2 = {name:'henry', gender:'m'}

Well, we have to copy each property of the objects into a new object. So, finally, the general function to merge two arrays/objects in javascript:

var mergeObjects = function(objOne, objTwo) {

        if (objOne instanceof Array) {

            return objOne.concat(objTwo);

        }

        var merge = {};

        var property;

        for (property in objOne) {

            merge[property] = objOne[property];

        }

        for (property in objTwo) {

            merge[property] = objTwo[property];

        }

        return merge;

}

That is it. It is easy to be modified to be more generic and robust.