JavaScript/jQuery : Check if two values are equal regardless of data type?

Question

我有一个 if 条件，我需要检查 A 是否与 B 具有相同的值，无论数据类型如何，例如

if (A == B) {
   //body of if statement
}

但是如果存在 ==，服务器检查验证将拒绝。它会要求将其更改为 === (但我无法更改它)。

我如何实现这一点，其中 A 和 B 的可能值和类型是

String, Number, null, '', undefined, NaN

看起来很简单，但可能只是一个逻辑错误......:)

Answer 1

从根本上来说，== 存在有效的用例，因此我建议找到任何可以更改该规则的人，并让他们这样做。

如果没有，您可以自己编写一个函数来执行 == 的功能，称为 abstract equality comparison algorithm ，然后使用该函数而不是 ==:

The comparison x == y, where x and y are values, produces true or false. Such a comparison is performed as follows:

1. If Type(x) is the same as Type(y), then
   1. Return the result of performing Strict Equality Comparison x === y.
2. If x is null and y is undefined, return true.
3. If x is undefined and y is null, return true.
4. If Type(x) is Number and Type(y) is String, return the result of the comparison x == ToNumber(y).
5. If Type(x) is String and Type(y) is Number, return the result of the comparison ToNumber(x) == y.
6. If Type(x) is Boolean, return the result of the comparison ToNumber(x) == y.
7. If Type(y) is Boolean, return the result of the comparison x == ToNumber(y).
8. If Type(x) is either String, Number, or Symbol and Type(y) is Object, return the result of the comparison x == ToPrimitive(y).
9. If Type(x) is Object and Type(y) is either String, Number, or Symbol, return the result of the comparison ToPrimitive(x) == y.
10. Return false.

规范中明确定义了上面使用的每个抽象操作的确切实现。