extend namespaces javascript

namespaces.js

// top-level namespace being assigned an object literal  
var myApp = myApp || {};  
// a convenience function for parsing string namespaces and  
// automatically generating nested namespaces  
function extend( ns, ns_string ) {  
    var parts = ns_string.split('.'),  
        parent = ns,  
        pl, i;  
    if (parts[0] == "myApp") {  
        parts = parts.slice(1);  
    }  
    pl = parts.length;  
    for (i = 0; i < pl; i++) {  
        //create a property if it doesnt exist  
        if (typeof parent[parts[i]] == 'undefined') {  
            parent[parts[i]] = {};  
        }  
        parent = parent[parts[i]];  
    }  
    return parent;  
}  
// sample usage:  
// extend myApp with a deeply nested namespace  
var mod = extend(myApp, 'myApp.modules.module2');  
// the correct object with nested depths is output  
console.log(mod);  
// minor test to check the instance of mod can also  
// be used outside of the myApp namesapce as a clone  
// that includes the extensions  
console.log(mod == myApp.modules.module2); //true  
// further demonstration of easier nested namespace  
// assignment using extend  
extend(myApp, 'moduleA.moduleB.moduleC.moduleD');  
extend(myApp, 'longer.version.looks.like.this');  
console.log(myApp);