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鍏堟潵涓伒榄傛嫹闂細鈥?strong>鈥嬩负浠€涔堝悓鏍烽兘鏄亶鍘嗗璞★紝杩欎袱涓柟娉曚細鎵笂鎬ц兘闂锛熲€?/strong>鈥?鍜变滑鐢ㄤ釜鐩镐翰甯傚満鐨勪緥瀛愭潵瑙ｉ噴锛?/p>

鈥?strong>鈥媐or...in鈥?/strong>鈥嬪氨鍍忎釜鑰佸疄浜猴紝浼氭妸瀵硅薄鍏ㄥ鑰佸皬锛堝寘鎷粠鍘熷瀷閾剧户鎵跨殑灞炴€э級閮戒粙缁嶇粰浣犮€傝€屸€?strong>鈥婳bject.keys()鈥?/strong>鈥嬪氨鍍忎釜绮炬槑濯掑﹩锛屽彧缁欎綘浠嬬粛瀵硅薄鑷繁浜茬敓鐨勫睘鎬с€?/p>

涓句釜鏍楀瓙馃尠锛?/p>

javascript澶嶅埗
const 鎵嬫満 = {鍨嬪彿:'Mate60', 浠锋牸:6999};
Object.prototype.淇濅慨鏈?= '2骞?; 

// for...in浼氭樉绀轰繚淇湡
for(let key in 鎵嬫満) { console.log(key) } // 鍨嬪彿銆佷环鏍笺€佷繚淇湡

// Object.keys()鍙浜插効瀛?/span>
Object.keys(鎵嬫満).forEach(key => console.log(key)) // 鍨嬪彿銆佷环鏍?/span>

鈥?strong>鈥嬮噸鐐规潵浜嗏€?/strong>鈥嬶細澶氭煡鎴峰彛鏈綋鐒惰垂鏃堕棿鍟婏紒杩欏氨鏄€ц兘宸紓鐨勬牴婧愩€?/p>

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鍜变滑鐩存帴涓婄‖璐э紒鐢?0涓囨潯鏁版嵁鍋氫釜鎿傚彴璧涳細

鏂规硶	Chrome鑰楁椂	Node.js鑰楁椂	鍐呭瓨鍗犵敤
for...in	152ms	168ms	2.8MB
Object.keys()+寰幆	128ms	142ms	1.9MB
Object.entries()	210ms	225ms	3.1MB

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鈥?strong>鈥嬩綘鍝侊紝浣犵粏鍝佲€?/strong>鈥嬶細Object.keys()缁勫悎鎷虫瘮for...in蹇簡灏嗚繎20%锛佺壒鍒槸鍐呭瓨鍗犵敤灏戜簡涓夊垎涔嬩竴锛岃繖瀵规墜鏈虹缃戦〉绠€鐩存槸鏁戝懡绋昏崏銆?/p>

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馃绗笁鍥炲悎锛氫负浠€涔堜細鏈夎繖绉嶅樊寮傦紵

鏉ヤ釜鎶€鏈畢瑙嗚鐨勮В璇伙細

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2. 鈥?strong>鈥嬫暟鎹粨鏋勨€?/strong>鈥嬶細V8寮曟搸鍐呴儴鎶婂璞″睘鎬у垎鎴愨€?strong>鈥嬫帓搴忓睘鎬?elements)鈥?/strong>鈥嬪拰鈥?strong>鈥嬪父瑙勫睘鎬?properties)鈥?/strong>鈥嬶紝for...in闇€瑕佸鐞嗚繖涓ょ缁撴瀯鐨勫崗璋冿紝灏卞儚鍚屾椂鎿嶄綔Excel琛ㄦ牸鍜岃浜嬫湰銆?/li>
3. 鈥?strong>鈥嬪唴瀛樺垎閰嶁€?/strong>鈥嬶細Object.keys()涓€娆℃€х敓鎴愭暟缁勫悗锛孋PU鍙互鎰夊揩鍦拌蛋楂橀€熺紦瀛橈紝鑰宖or...in灏卞儚鍦ㄤ埂闂村皬璺弽澶嶇粫寮€?/li>

馃殌绗洓鍥炲悎锛氬疄鎴樹腑鐨勯獨鎿嶄綔

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javascript澶嶅埗
// 鍘熷鍐欐硶锛堣鍛界増锛?/span>
const 鍟嗗搧鏁版嵁 = {/* 瓒呭ぇ鏁版嵁 */};
for(const key in 鍟嗗搧鏁版嵁){
  if(鍟嗗搧鏁版嵁.hasOwnProperty(key)) { // 姣忔閮借鏌ユ埛鍙ｏ紒锛?/span>
    // 澶勭悊鏁版嵁...
  }
}

// 浼樺寲鐗堬紙璧烽妯″紡锛?/span>
const keys = Object.keys(鍟嗗搧鏁版嵁); // 鍏堟嬁閽ュ寵涓?/span>
for(let i=0; ilength; i++){  // 鑰佹淳for寰幆鏈€蹇?/span>
  const key = keys[i];
  // 鐩存帴寮€骞诧紒
}

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馃绗簲鍥炲悎锛氫粈涔堟椂鍊欒鐢╢or...in锛?/h3>

铏界劧Object.keys()寰堥锛屼絾鏈変簺鍦哄悎杩樼湡绂讳笉寮€for...in锛?/p>

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馃懆馃捇鐙瑙佽В锛?025骞寸殑鏂板彂鐜?/h3>

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馃寛鍐欏湪鏈€鍚?/h3>

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