The difference between jquery (function () {}) and (function () {}) (jquery)

$ (document). Ready (function () {  //write your code here ...});

Code to run when the DOM load is complete

can be simply written

What does (function ($) {}) (jQuery) mean?

(function () {}) (JQuery);

It is actually an anonymous method of executing () (para), except that the jquery object is passed.

Equivalent

function AA ($) {} AA (JQuery)

Is the usual way to initialize jquery objects.

(Funtion () {}) (); Execute the function immediately; the equivalent of declaring a function first and calling it directly after the declaration is finished;

If the parameters are as follows:

(Funtion (str) {alert (str)}) ("Output")) ；

Equivalent:

Funtion Outputfun (str) {alert (str);};o Utputfun ("Output");

(function ($) {...}) (JQuery) is actually an anonymous function
This is actually anonymous function functions (ARG) {...} This defines an anonymous function that, when called with Arg, is written with parentheses and arguments after the function, and because of the precedence of the operator, the function itself needs to be enclosed in parentheses, namely: (function (ARG) {...}) (param) This is equivalent to defining an anonymous function with a parameter of ARG, and calling this anonymous function as a parameter (function ($) {...}) param (jquery) is the same, the reason that only use $ in formal parameters is to not conflict with other libraries, so the argument with JQuery, equivalent to:

var fn = function ($) {...}; FN (jQuery);

Summarize:

JQuery (function () {}), which holds the code for manipulating the DOM object, and the DOM object already exists when the code executes it. cannot be used to store code that develops plug-ins, because jquery objects are not passed, and external methods (functions) cannot be called by Jquery.method.

(function () {}) (JQuery), which is used to store the code that develops the plug-in, and the DOM does not necessarily exist when executing the code, so be careful with the code that automatically executes DOM operations directly.

The difference between jquery (function () {}) and (function () {}) (jquery)