看起来相同的字符串不相等 [英] Strings that look the same aren't equal

问题描述

某些单元测试失败.调试后，我在这里找到了问题

Some unit tests are failing. Upon debugging, I traced the problem here

var a = "USD 1,234.12"
var b = "USD 1,234.12"
console.log(a === b)

String a 是由货币格式化程序库生成的，而String b 是由单元测试开发人员编写的.

String a has been generated by a currency formatter library and String b has been written by a unit test developer.

我不明白为什么 === 不能将这两个看起来相同的字符串视为相等.这是怎么回事?

I don't understand why these two strings that look the same aren't considered equal by ===. What is happening here?

推荐答案

您的两个字符串有一个隐藏的区别.运行此:

There's a hidden difference in your two strings. Run this:

var a = "USD 1,234.12"
var b = "USD 1,234.12"

for (var i = 0; i < a.length; i++) {
  console.log(a.codePointAt(i), b.codePointAt(i));
}

b 字符串中的空格是常规空格(32)，而 a 字符串中的空格是Unicode不间断空格(160).

The space in the b string is a regular space (32), while the space in the a string is a Unicode non-breaking space (160).

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