JavaScript中的删除运算符 [英] the delete operator in javascript

问题描述

我想问有关Java语言中删除"运算符的问题

I would like to ask questions about 'delete' operator in Javascript

为什么

delete window.document; // returns false

但是

delete navigator.geolocation; // returns true

我尝试了 navigator 的其他属性，但它仍然返回 true

I try other properties of navigator and it still returns true

我已经检查了Webkit中的IDL， document 和 navigator 均为只读，
而且他们没有DontDelete属性但是为什么我可以删除一个而不删除另一个??

I have checked the IDL in webkit, document and navigator are both of readonly,
and they dont have DontDelete attribute but why I can delete one but not for the other???

推荐答案

如果您想了解 delete 运算符，请紧记

If you'd like to understand the delete operator, wrap your mind around the javascript spec section 11.4.1

在许多情况下，操作员应评估为 true 而不改变任何对象.

There are several cases where the operator should evaluate to true without mutating any objects.

从8.12.7开始，操作员检查检查属性描述符的内部 [[Configurable]] 属性以强制执行只读属性.

From 8.12.7, the operator checks checks an internal [[Configurable]] property of the property descriptor to enforce readonly properties.

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