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/global_objects/map/has/index.html | 120 +++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 files/zh-cn/web/javascript/reference/global_objects/map/has/index.html (limited to 'files/zh-cn/web/javascript/reference/global_objects/map/has/index.html') diff --git a/files/zh-cn/web/javascript/reference/global_objects/map/has/index.html b/files/zh-cn/web/javascript/reference/global_objects/map/has/index.html new file mode 100644 index 0000000000..73eb4550d0 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/global_objects/map/has/index.html @@ -0,0 +1,120 @@ +--- +title: Map.prototype.has() +slug: Web/JavaScript/Reference/Global_Objects/Map/has +tags: + - ECMAScript 2015 + - JavaScript + - Map + - Method + - Reference +translation_of: Web/JavaScript/Reference/Global_Objects/Map/has +--- +
{{JSRef}}
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方法has() 返回一个bool值,用来表明map 中是否存在指定元素.

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语法

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myMap.has(key);
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参数

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+
key
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必填. 用来检测是否存在指定元素的键值.
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返回值

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Boolean
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如果指定元素存在于Map中,则返回true。其他情况返回false
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案例

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使用has方法

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var myMap = new Map();
+myMap.set("bar", "foo");
+
+myMap.has("bar");  // returns true
+myMap.has("baz");  // returns false
+
+ +

规范列表

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规范名称StatusComment
{{SpecName('ES6', '#sec-map.prototype.has', 'Map.prototype.has')}}{{Spec2('ES6')}}Initial definition.
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浏览器兼容性

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{{CompatibilityTable}}

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浏览器Chrome谷歌Firefox (Gecko)火狐Internet ExplorerOperaSafari
兼容版本38{{CompatGeckoDesktop("13.0")}}11257.1
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浏览器AndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
兼容版本{{CompatNo}}38{{CompatGeckoMobile("13.0")}}{{CompatNo}}{{CompatNo}}8
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相关链接

+ + -- cgit v1.2.3-54-g00ecf