严格不等式 (!==)

¥Syntax

x !== y

¥Description

严格不等运算符检查其操作数是否不相等。它是 严格平等 运算符的否定，因此以下两行将始终给出相同的结果：

¥The strict inequality operator checks whether its operands are not equal. It is the negation of the strict equality operator so the following two lines will always give the same result:

x !== y;

!(x === y);

比较算法的详细信息请参见 严格平等 算子页面。

¥For details of the comparison algorithm, see the page for the strict equality operator.

与严格相等运算符一样，严格不等运算符始终将不同类型的操作数视为不同的：

¥Like the strict equality operator, the strict inequality operator will always consider operands of different types to be different:

3 !== "3"; // true

¥Examples

¥Comparing operands of the same type

"hello" !== "hello"; // false
"hello" !== "hola"; // true

3 !== 3; // false
3 !== 4; // true

true !== true; // false
true !== false; // true

null !== null; // false

¥Comparing operands of different types

"3" !== 3; // true
true !== 1; // true
null !== undefined; // true

¥Comparing objects

const object1 = {
  key: "value",
};

const object2 = {
  key: "value",
};

console.log(object1 !== object2); // true
console.log(object1 !== object1); // false

¥See also

• 平等（==）
• 不平等（!=）
• 严格平等 (===)