jQuery 新手:jQuery(function($) { ... }) 是什么意思? [英] jQuery newbie: what does jQuery(function($) { ... }) means?

问题描述

我知道在 jQuery 中，$(callback) 和 jQuery(callback) 是一样的，它和 $(document).ready().

I know in jQuery, $(callback) is the same as jQuery(callback) which has the same effect as $(document).ready().

怎么样

jQuery(function($) {

 });

谁能给我解释一下这种功能是什么意思?

Can some one explain to me what does this kind of function mean?

它有什么作用?

这个和$(callback)有什么区别??

这个和$(function())有什么区别??

推荐答案

jQuery(function($) {

});

是三者中最安全的版本.它使 $ 成为局部变量，从而优雅地避免与任何其他可能使用 $ 符号的变量发生冲突.

is the safest version of all three. It makes $ the local variable and thus gracefully avoids the conflicts with any other variables which possibly use $ symbol.

我想它也是最近添加的，不记得以前看过了.

I think it was also added fairly recently, don't remember seeing it before.

这些函数都做同样的事情——在 DOM 准备好时执行一些代码.$(document).ready(function(){}) 是原始的，它匹配底层的javascript API.

These function all do the same things - execute some code when DOM is ready. $(document).ready(function(){}) is the original one, and it matches the underlying javascript API.

"$" 和 "jQuery" 接受函数作为参数被创建为快捷方式，以避免重复这种常见的构造.接受一个接受 $ 作为其第一个参数的函数是一种进一步的语法糖 - 现在您可以方便地使用闭包，而无需自己动手.

"$" and "jQuery" which accept function as an arguments were created as shortcuts to avoid repeating such a common construct. Accepting a function which accepts $ as its first argument is a further syntax sugar - now you get convenience of the closures without the need to do it yourself.

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