Code I don't understand.

ChicagoBobT

I am looking over some code that someone else wrote for three.js The main.js file starts out with this.

var APP = {};

(function () {
"use strict";

/*global VT,THREE,Detector,requestAnimationFrame*/
/*jslint browser: true*/

/***************************************************************************
* Global Variables
*/

// three.js variables
var scene = null;
var renderer = null;
var camera = null;
var controls = null;
var mesh = null;
var clock = new THREE.Clock();

var domContainer = null;
var virtualTexture = null;

/***************************************************************************
* Initialiaze application
*/

function resize() {
renderer.setSize(window.innerWidth, window.innerHeight);
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
}

.
.
.
APP.load = function (geometry, config) {

// create virtual texture
geometry.computeTangents();
geometry.computeVertexNormals();

virtualTexture = new THREE.VirtualTexture(renderer.context, config);
var material = THREE.createVirtualTextureMaterial(virtualTexture);

mesh = new THREE.Mesh(geometry, material);
scene.add(mesh);

THREE.duplicateGeometryForVirtualTexturing(geometry, virtualTexture);

};

}());

and the code ends like above. I dont get this line (function () { How does that work or even get called? The code actually works and not seeing anything like this before just made me curious. Hope someone can shed some light on this. Thanks, Bob

Graham Breach

All of the code is encapsulated inside an anonymous function that starts with the

(function () {

line and ends with

}());

The function is executed straight away - the () on the last line calls it with no arguments. The only variable that this script exposes is "APP", which is an object containing the "load" function (and anything else that was added in the ... part).

ChicagoBobT

Thanks so much.

Anlige

(function () {
/*TODO*/
}());

equal with:

var fn = function(){
/*TODO*/
};
fn();

look at the following codes:

(function(words){alert(words);}('hello!'));

Sunasara Imdadhusen

Really good explanation

Suresh Amudalapalli

It’s an Immediately-Invoked Function Expression, or shorter: IIFE. It executes immediately after it’s created. This pattern is often used when trying to avoid polluting the global namespace, because all the variables used in the function are not visible outside its scope.

Lost User

Nice explanation :)