使用“return！0”是否有任何意义？在JavaScript中？ [英] Is there any point of using "return !0" in javascript?

问题描述

如果您转到Google结果页并运行 rwt.toString（），您会看到此函数的返回调用是：

If you go to a google result page, and run rwt.toString(), you'll see that the return call for this function is:

return !0;

我想不出为什么这不会总是真。这只是 true 的简写，还是有更多的进展？

I can't think of any reason why this wouldn't always be true. Is this just a shorthand for true, or is there more going on here?

推荐答案

总是如此，但需要2个字节才能下载（！0 是2个字符）而不是4个字节来下载布尔值 true 。

It is always true, but it takes 2 bytes to download (!0 is 2 characters) instead of 4 bytes to download the boolean value true.

大多数Javascript minifiers将 true 转换为！0 和false ！1 。您可以通过在Google的Closure Compiler上使用简单优化键入 var y = true; 来查看此示例： http://closure-compiler.appspot.com/home

Most Javascript minifiers will convert true to !0 and false to !1. You can see an example of this by typing var y = true; with Simple optimizations on Google's Closure Compiler: http://closure-compiler.appspot.com/home

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