为什么浏览器不抛出一个错误时，任何其他字是用来代替’javascript’在 onclick 的值？

我继承了一个网站，然后发现了这个好奇心:

<a href="/delete"  onClick="jamoscript:return confirm('Do you really want to do that?');">Delete all</a>

我可以显示包含它的页面，并点击链接获得确认对话框完全一样，当我改变“ jamoscript”为“ javascript”。在加载页面或单击链接时，Firebug 控制台中不显示任何诊断信息。搞什么？搜索 jamoscript 没有任何有趣的发现。

有人能解释一下这种行为吗？

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最佳答案

The string value of an "onclick" attribute is taken to be simple JavaScript code. JavaScript includes provisions for labeled statements, so that code is a return statement with the label "jamoscript". In other words, this:

jamoscript: return confirm("Do you really want to hurt me?");

is perfectly legal JavaScript. Labels aren't used much, so they're unfamiliar.

The only context in which the "javascript:" prefix matters is when a URL is expected, as is the case with the "href" attribute of <a> tags.