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©.
set() 㯠Map ã¤ã³ã¹ã¿ã³ã¹ã®ã¡ã½ããã§ãæå®ããããã¼ã¨å¤ãæã¤è¦ç´ ããã® Map ãªãã¸ã§ã¯ãã«è¿½å ããããæ´æ°ããããã¾ãã
試ãã¦ã¿ã¾ããã
const map = new Map();
map.set("bar", "foo");
console.log(map.get("bar"));
// äºæ³ãããçµæ: "foo"
console.log(map.get("baz"));
// äºæ³ãããçµæ: undefined
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set(key, value)
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key-
Mapãªãã¸ã§ã¯ãã«è¿½å ããè¦ç´ ã®ãã¼ã§ãããã¼ã¯ããããã® JavaScript å ï¼ããããã®ããªããã£ãå¤ã¾ãã¯ä»»æã®åã® JavaScript ãªãã¸ã§ã¯ãï¼ã§ãã value-
Mapãªãã¸ã§ã¯ãã«è¿½å ããè¦ç´ ã®å¤ã§ããå¤ã¯ããããã® JavaScript å ï¼ããããã®ããªããã£ãå¤ã¾ãã¯ä»»æã®åã® JavaScript ãªãã¸ã§ã¯ãï¼ã§ãã
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Map ãªãã¸ã§ã¯ãã§ãã
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set() ã®ä½¿ç¨
const myMap = new Map();
// ãããã«æ°ããè¦ç´ ã追å ãã
myMap.set("bar", "foo");
myMap.set(1, "foobar");
// ãããã«ããè¦ç´ ãæ´æ°ãã
myMap.set("bar", "baz");
set() ã®ã¡ã½ãããã§ã¼ã³ã®ä½¿ç¨
set() ã¡ã½ãã㯠Map ãªãã¸ã§ã¯ããè¿ãããã以ä¸ã®ããã«ã¡ã½ãããã§ã¼ã³ãä½ããã¨ãã§ãã¾ãã
// ãã§ã¼ã³ã使ç¨ãã¦ãããã«æ°ããè¦ç´ ã追å ãã
myMap.set("bar", "foo").set(1, "foobar").set(2, "baz");
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| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-map.prototype.set |