(function () {}) ();, xx=xx| | {}; the definition and role!

Recent projects have encountered this problem, by the way record!

Find the information on the Internet to understand understanding, give my understanding as follows:

Question 1:

(function () {}) (): This function () {} represents an anonymous one, and () wraps the functions () {}, () representing the highest priority execution, which takes precedence over the function () {}. The last () means that the function () { } is called immediately after executing function () {}.

Like what:

If function () {} is compared to function xx () {}, () represents XX (), the defined XX function is called.

Case:

(function () {
Alert (0)
})();

Result: the frame shows 0;

(function () {
Alert (0)
});

Results: no box display 0;

Question 2:

xx=xx| | {};//means declaring a command space called XX (Defining a global variable--in JavaScript, variables that are not declared with VAR are treated as global variables ).

xx.kk= (function () {

Xx.yy=function () {///Declare a namespace called XX.YY (the object in the closure is passed to the global variable through the addition of the global variable, which results in a code encapsulation

return "XXX";

};

var data1= "";

(function () {

data1= "XXX";

})();

return {DATA1:DATA1};

})();

-----------Call

Alert (Xx.yy ());

Or

alert (XX.KK.DATA1);

(function () {}) ();, xx=xx| | {}; the definition and role!