使用$的多个图书馆的javascript结果如何？
[英]What is the outcome in javascript with multiple librarys that use $
问题描述
Let's pretend this is in the <head> of your html page. 
让我们假装这是在你的html页面的<head>中。
OOPS this was a bit that was missing before... : OOPS之前有点遗漏...... ：
<script type="text/javascript" src="/include/js/billys.js"></script>
<script type="text/javascript" src="/include/js/susies.js"></script>
<script type="text/javascript" src="/include/js/marys.js"></script>
Order of the 3 scripts could vary. 3个脚本的顺序可能会有所不同。 What would be the outcome? 会有什么结果？
Billy defines $ as 比利将$定义为
function $ () {
return false;
}
Susie defines $ as 苏西将$定义为
function $ () {
return document.getElementById('body');
}
Mary defines $ as 玛丽将$定义为
function $ () {
alert('I wrote this');
}
3 个解决方案
解决方案1
18 已采纳 2011-05-11 19:42:26
Whatever is last is the final definition of $ 无论什么是最后的是$的最终定义
That is why in (for example) jQuery there is noConflict() which lets you use a different variable than $ for jQuery 这就是为什么在（例如）jQuery中有noConflict()允许你使用不同的变量而不是$ for jQuery
解决方案2
16 2011-05-11 19:44:13
function $ () {
return false;
}
function $ () {
return document.getElementById('body');
}
function $ () {
alert('I wrote this');
}
$(); // alerts "I wrote this"
The later definition overwrites the existing one. 后面的定义会覆盖现有的定义。 This is why it's generally good practice to check whether a function already exists before defining it. 这就是为什么在定义函数之前检查函数是否已存在的一般做法。 eg 例如
if (typeof $ !== 'function') {
function $(){ /* your code */}
}
or to fail in some sensible way. 或以某种明智的方式失败。
解决方案3
5 2011-05-11 19:43:29
最后一个具有相同名称的函数获胜。
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