js deepCopy

goodCode.js

var a = 1;
var b = ++a; // b = 2, a = 2;
a = 1;
b = a++; // b = 1; a = 2;


function deepCopy() (parent, child) {
	var i,
		toStr = Object.propotype.toString,
		// x: arrName = '[Object Array]';
		arrName = '[object Array]';
	
	// forget check child if null 
	child = child || {};

	for( i in parent ) {
		if( parent.hasOwnProerty[i] ) {
			if(typeof parent[i] === "object") {
				child[i] = (toStr.call(parent[i]) === arrName) ? [] : {};
				deepCopy(parent[i],child[i]);
			} else {
				child[i] = parent[i];
			}
		}
	}
	return child;
}