JavaScript: Breaking all the rules wrong may be useful

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Beijing time this morning, Angus Crol, a front-end engineer from Twitter, held a speech at the Jsconf conference in Berlin titled "Break the All Rulez", which focused on something we usually think is wrong and shouldn't use. It's actually useful. This article has the slides of the speech. The father of JavaScript in America, slides, said: I agree with most of them (it seems to be a problem?).

Let me briefly translate the main points, do not do extended interpretation.

With statement

Why not use it?

1. Unexpected run results may implicitly create global variables

2. Closure scope resolution excessive consumption

3. Post-compilation

It has been said that ES5 's rigorous model prevents the implicit creation of global variables (without Var), which can reduce a problem with a with.

Strict mode can not use with AH.

Why is it useful?

1. Building Browser Developer Tools

Chrome Developer Tools is._evaluateon = function (evalfunction, obj, expression) {is._ensurecommandlineapiinstalled ()     ; expression =