onClick="javascript: function('value')'" 和 onClick="function('value');" 有什么区别？
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What is the difference between onClick="javascript: function('value')'" and onClick="function('value');"?
提问by Jalpesh Patel
What is the difference between the following?
以下有什么区别？
onClick="javascript: function('value');"onClick="function('value');"
onClick="javascript: function('value');"onClick="function('value');"
When do I use the javascript:before the function call, and why?
我什么javascript:时候在函数调用之前使用，为什么？
Can I call the function without using javascript:prefix?
我可以在不使用javascript:前缀的情况下调用该函数吗？
Please help me understand the difference.
请帮助我理解其中的区别。
回答by nnnnnn
In an element's inline event handler, like onclick, onchange, onsubmit, etc., you do notneed the javascript:prefix - the reason you often see it is because people confuse it with the hrefsyntax that I explain below. It doesn't cause an error - I believe it is interpreted as a label- but it is unnecessary.
在一个元素的内联事件处理程序，像onclick，onchange，onsubmit等等，你不是需要的javascript:前缀-你经常看到这是因为人们与混淆的原因href语法，我在下面解释。它不会导致错误 - 我相信它被解释为一个标签- 但它是不必要的。
It doesn't matter whether you want to call a function or run a "simple" JS statement, either way don't include javascript:- that is, all three of these are valid:
无论您是要调用函数还是运行“简单”的 JS 语句都没有关系，无论哪种方式都不要包含javascript:- 也就是说，所有这三个都是有效的：
onclick="doSomething('some val');"
onclick="return false;"
onclick="doSomething(); doSomethingElse(); return false;"
If you are using inline event attributes don't use the javascript:prefix.
如果您使用内联事件属性，请不要使用javascript:前缀。
(I say "ifyou are using inline event attributes" because this practice is really outdated: it is better to assign the event handlers using JS in a script block.)
（我说“如果你使用内联事件属性”是因为这种做法真的已经过时了：最好在脚本块中使用 JS 分配事件处理程序。）
You only need the javascript:prefix when you want to run JavaScript from an <a>element's hrefattribute like this:
javascript:当您想从<a>元素的href属性运行 JavaScript 时，您只需要前缀，如下所示：
<a href="javascript: someFunc();">Whatever</a>
That is because the browser normally expects the hrefto contain a URI, so the javascript:prefix tells it to expect JS code instead. However, I don't recommending doing that because the page won't work for people who have JS disabled. Better to include an hrefthat directs the user to a page telling them to enable JS, and include an onclickto do the JS functionality:
那是因为浏览器通常期望href包含一个 URI，所以javascript:前缀告诉它期望 JS 代码。但是，我不建议这样做，因为该页面不适用于禁用 JS 的人。最好包含一个href将用户引导到告诉他们启用 JS 的页面，并包含一个onclick执行 JS 功能的页面：
<a href="/enableJS.html" onclick="doSomething(); return false;">Whatever</a>
That way the link does something useful for users whether they have JS enabled or not. The return falseat the end of the click handler prevents the default behaviour for a click (which would be to navigate to the specified URL).
这样，无论用户是否启用了 JS，该链接都会对用户有用。将return false在单击处理防止年底点击默认行为（这将是导航到指定的URL）。
回答by Quentin
The first one has a completely redundant label.
第一个有一个完全多余的标签。
When should i have to use the "javascript:" before the function call and what is the reason of use it?
我什么时候应该在函数调用之前使用“javascript：”，使用它的原因是什么？
Never. (Well, almost. You do use it in javascript:scheme URIs, but you should only use those if you are writing a bookmarklet, and they wouldn't appear in an onclickattribute).
绝不。（嗯，差不多。您确实在javascript:方案 URI 中使用了它，但是只有在编写书签时才应该使用它们，并且它们不会出现在onclick属性中）。
(javascript:URIs are where the cargo-cultpractice of prefixing onclickattribute values with a label came from.)
（javascript:URI 是用标签作为属性值前缀的货物崇拜实践的onclick来源。）
can i call the function without using "javascript:"??
我可以在不使用“javascript:”的情况下调用该函数吗？？
Yes.
是的。
