From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- .../reference/operators/inequality/index.html | 104 +++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 files/zh-cn/web/javascript/reference/operators/inequality/index.html (limited to 'files/zh-cn/web/javascript/reference/operators/inequality') diff --git a/files/zh-cn/web/javascript/reference/operators/inequality/index.html b/files/zh-cn/web/javascript/reference/operators/inequality/index.html new file mode 100644 index 0000000000..2c0bccddfd --- /dev/null +++ b/files/zh-cn/web/javascript/reference/operators/inequality/index.html @@ -0,0 +1,104 @@ +--- +title: 不等于 (!=) +slug: Web/JavaScript/Reference/Operators/Inequality +tags: + - JavaScript + - 参考 + - 语言特征 + - 运算符 +translation_of: Web/JavaScript/Reference/Operators/Inequality +--- +
{{jsSidebar("Operators")}}
+ +

不等于运算符 (!=) 检查其两个操作数是否不相等,并返回布尔结果。 与严格的不等式运算符不同,它尝试转换和比较不同类型的操作数。

+ +
{{EmbedInteractiveExample("pages/js/expressions-inequality.html")}}
+ + + +

语法

+ +
x != y
+ +

描述

+ +

不等式运算符检查其操作数是否不相等。这是等于运算符的取反,因此以下两行将始终给出相同的结果: 

+ +
x != y
+
+!(x == y)
+ +

有关比较算法的详细信息,请参见等于运算符的页面

+ +

与等于运算符一样,不等于运算符将尝试转换和比较不同类型的操作数:

+ +
3 != "3"; // false
+ +

为避免这种情况,并要求将不同类型视为不同,请使用严格的不等于运算符:

+ +
3 !== "3"; // true
+ +

例子

+ +

没有类型转换的比较

+ +
1 != 2;              // true
+"hello" != "hola";   // true
+
+1 != 1;              // false
+"hello" != "hello";  // false
+ +

与类型转换比较

+ +
"1" !=  1;            // false
+1 != "1";             // false
+0 != false;           // false
+0 != null;            // true
+0 != undefined;       // true
+0 != !!null;          // false, look at Logical NOT operator
+0 != !!undefined;     // false, look at Logical NOT operator
+null != undefined;    // false
+
+const number1 = new Number(3);
+const number2 = new Number(3);
+number1 != 3;         // false
+number1 != number2;   // true
+ +

对象比较

+ +
const object1 = {"key": "value"}
+const object2 = {"key": "value"};
+
+object1 != object2 // true
+object2 != object2 // false
+ +

规范

+ + + + + + + + + + +
Specification
{{SpecName('ESDraft', '#sec-equality-operators', 'Equality operators')}}
+ +

浏览器兼容性

+ + + +

{{Compat("javascript.operators.inequality")}}

+ +

参见

+ + + +
+
+
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