为什么将null作为字符串存储在localStorage中? [英] Why is null stored as a string in localStorage?

问题描述

在Chrome控制台中，我将foo设置为null:

In the Chrome console I set foo to null:

localStorage.setItem("foo",null)

然后我测试是否为空:

console.log(localStorage.getItem("foo")==null)

打印false.

然后我测试是否是字符串"null":

Then I test, whether it is the string "null":

console.log(localStorage.getItem("foo")=="null")

打印true.

我认为null是合法的Javascript值.当我在浏览器中手动清除localStorage时，将其存储为字符串"null"非常直观，并且在其他可以正常运行的程序中引起了奇怪的错误.

I thought that null was a legitimate Javascript value. Storing it as the string "null" is very counter intuitive and caused a strange bug in an otherwise working program, when I cleared the localStorage in the browser manually.

推荐答案

按照 setter 方法转换为setItem，仅接受DOMString

setter method translates to setItem, accepts only DOMString

根据文档

DOMString是UTF-16字符串.由于JavaScript已经使用了这样的字符串， DOMString直接映射到字符串.

DOMString is a UTF-16 String. As JavaScript already uses such strings, DOMString is mapped directly to a String.

将null传递给通常接受DOMString的方法或参数 字符串化为"null".

Passing null to a method or parameter accepting a DOMString typically stringifies to "null".

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