57 lines
1.4 KiB
Markdown
57 lines
1.4 KiB
Markdown
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---
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title: Object Is
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localeTitle: 对象是
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---
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# 对象是
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## 描述
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`object.is()`方法用于确定两个值是否相同。这种方法是在ES6中引入的。
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## 句法
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`Object.is(val1, val2)`
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### 参数
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**val1** - 要比较的第一个值
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**val2** - 要比较的第二个值
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## 返回值
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一个[布尔值,](https://guide.freecodecamp.org/javascript/booleans)指示两个参数是否具有相同的值
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## 描述
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`Object.is()`比较两个相同的值,如果两个值满足以下条件之一,则返回`true` :
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* `undefined`
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* `null`
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* 无论是`true`还是`false`
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* 具有相同长度和相同字符的字符串
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* 相同的对象
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* 这两个数字和:
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* `+0`或两者都是`-0`
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* 两个`NaN`
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* 或两者都不是零而不是`NaN`
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## 例子
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\`\`\`
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Object.is('string','string'); //真的 Object.is(undefined,undefined); //真的 Object.is(null,null); //真的
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Object.is('string,'word'); //假 Object.is(true,false); //假 Object.is(\[\],\[\]); //假
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var obj = {name:Jane}; Object.is(obj,obj); //真的
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Object.is(NaN,NaN); //真的
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Object.is(+ 0,-0); //假 Object.is(-0,-0); //真的
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\`\`\`
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#### 更多信息:
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[Object.is()MDN Web文档](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is) [严格的相等运算符`===`](https://guide.freecodecamp.org/certificates/comparison-with-the-strict-equality-operator)
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