Map.prototype.set()
Baseline
Widely available
This feature is well established and works across many devices and browser versions. Itâs been available across browsers since â¨2015å¹´7æâ©.
Map å®ä¾ç set() æ¹æ³ä¼å Map 对象添å ææ´æ°ä¸ä¸ªæå®çé®å¼å¯¹ã
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const map1 = new Map();
map1.set("bar", "foo");
console.log(map1.get("bar"));
// Expected output: "foo"
console.log(map1.get("baz"));
// Expected output: undefined
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js
set(key, value)
åæ°
key-
è¦æ·»å å°
Map对象çå ç´ çé®ã该å¼å¯ä»¥æ¯ä»»ä½ JavaScript ç±»åï¼ä»»ä½åå§å¼æä»»ä½ç±»åç JavaScript 对象ï¼ã value-
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Map对象çå ç´ çå¼ã该å¼å¯ä»¥æ¯ä»»ä½ JavaScript ç±»åï¼ä»»ä½åå§å¼æä»»ä½ç±»åç JavaScript 对象ï¼ã
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Map 对象ã
示ä¾
ä½¿ç¨ set()
js
const myMap = new Map();
// å°ä¸ä¸ªæ°å
ç´ æ·»å å° Map 对象
myMap.set("bar", "foo");
myMap.set(1, "foobar");
// å¨ Map 对象ä¸æ´æ°æ个å
ç´ çå¼
myMap.set("bar", "baz");
é¾å¼ä½¿ç¨ set()
å 为 set() æ¹æ³è¿å Map 对象æ¬èº«ï¼æä»¥ä½ å¯ä»¥åä¸é¢è¿æ ·é¾å¼è°ç¨å®ï¼
js
// é¾å¼æ·»å å
ç´
myMap.set("bar", "foo").set(1, "foobar").set(2, "baz");
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| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-map.prototype.set |