Question

以下两行之间是否有任何速度/效率差异。

$("table td:not(:first-child)")

以及

$("table td").not(":first-child")

I would think that the first would be better since it is removes objects, but is there an actual difference 以及is it substantial.

增编

Answer 1

参看jsperf测试,:not平均比快两倍。总的来说,这一业绩很可能是你总体执行时间的很小一部分。

The jquery docs state:

The .not() method will end up providing you with more readable selections than pushing complex selectors or variables into a :not() selector filter. In most cases, it is a better choice.

因此,由您来决定,第二位的分数是否大于可读性。

Answer 2

取决于浏览器。

Browsers that support querySelectorAll 将提高业绩......

$("table td:not(:first-child)")

......因为它是有效的甄选者。 (IE7和下限)。

您需要仔细阅读<代码>:not()。 j 质量(Sizzle)与非标准选择器一起推广,因此很容易打破<代码>qSA。

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