parse.com - what is this Javascript opening syntax? -

i'm doing tuts tutorial on intel xdk , parse , 1 of source files has syntax i've never seen anywhere. file opens function not has no name, declared inside regular parentheses. can explain and/or link online resource explains this?

(function (credentials) {      var exports = {};     var baseurl = 'https://api.parse.com/1/classes/article/';      exports.articles = function (params) {     params = params || {};     var artid = '';     if (params.id) {         artid = params.id;     }     var url = baseurl + artid;     return $.ajax({         url: url,         headers: {         'x-parse-application-id' : credentials.apikey,         'x-parse-rest-api-key' : credentials.apisecret         }     });     };       return exports; }) 

your code snippet many pointed out, missing pair of () @ end. (), becomes iife, wikipedia article pointed mike explains clearly.

in brief, immediately-invoked function expression executed once program encounters it. consider simple case below:

//your awesome js console.log(b); // undefined (function() {   b = "cat"; })(); console.log(b); // cat. since in above iife, defined global variable b. 

you can pass parameters iife this:

(function(input) {   console.log(input); // 5 })(5); 

your code above creates "export" object , returns it. if read "establishing private variables , accessors" section in wiki, you'll see how used nicely create "private" variables.