can anyone explain how this below works?
var MYAPP = {};
MYAPP.namespace = function(name){
var parts = name.split('.');
var current = MYAPP;
for (var i in parts) {
if (!current[parts[i]]) {
current[parts[i]] = {};
}
// shouldn't this line override the MYAPP object with all it's properties?
current = current[parts[i]];
}
}
current is first assigned a reference to MYAPP, after that, within the loop, for every part of the Array from name.split it is subsequently assigned a reference to the freshly made property of MYAPP. So nothing is overwritten, because it's all references.
in words for example if you execute MYAPP.namespace(foo.bar) this happens:
current points to MYAPPcurrent /*is ref to MYAPP*/ .foo doesn't exist, create MYAPP.foo current point to MYAPP.foocurrent /*is now ref to MYAPP.foo*/ .bar doesn't exist create itMYAPP contains:
MYAPP.foo MYAPP.foo.barMYAPP as MYAPP.namespace(foo.bar) using an object literal, you would write
var MYAPP = { foo: { bar: {} }
All this does really is initializing empty objects.
When you call MYAPP.namespace('foo.bar') it will create an empty object ({}) in MYAPP.foo and then again one in MYAPP.foo.bar. That way you can then add functions and variables into MYAPP.foo.bar.
The namespace method lets you create nested objects in the MYAPP object.
If you call MYAPP.namespace('foo.bar') it will:
MYAPP.foo exists, and create it if it doesn't.MYAPP.foo.bar exists, and create it if it doesn't.I will explain it with the code sample.
See this code var MYAPP = {} creates a global empty object if left like now.
MYAPP.namespace is a instance method for the object and can be used like MYAPP.namespace("foo.bar")
lets get into quick preview,
when i do this MYAPP.namespace("ice.cream")
it creates two inner objects by checking previous existence like MYAPP.ice.Cream which act individually
And Yes that line does override our initial MYAPP object, remove that line or abstract away the namespace method to global utils. something like Utils.registerNameSpace("MYAPP.Ice.Cream");
currentthat points toMYAPP. It doesn't overwrite the valueMYAPP