javascript - 预期为 '===' 而看到的是 '==' eqeqeq

Question

这个问题在这里已经有了答案:





Which equals operator (== vs ===) should be used in JavaScript comparisons?

(48 个回答)


2年前关闭。

if (customer === "new") {
  //run code
} else {
}

当我运行这个条件时，它运行我的代码，而实际上我在客户“customername”中有字符串值，并与不等于 ("customername" != "new") 的 sring “new”进行比较它不应该在比较时运行代码。
我发现使用 === equal 将检查类型，如果类型相同，它将传递 true 所以 == 是检查值的选项，但我在使用 == 时遇到错误.

Expected '===' and instead saw '=='  eqeqeq

Answer 1

我认为您正在使用 JSHint，“eqeqeq”是确保使用严格相等运算符的选项。

来自 here :

The JSHint eqeqeq option is used to prohibit the use of the equals operator == and the does-not-equal operator !=. This enforces the use of the strict equality operators (=== and !== instead). The strict equality operators differ from their non-strict counterparts by first comparing the type of each operand, rather than attempting to coerce them to a common type. In the following example we make use of the non-strict equality operator to check whether a value is either null or undefined