1.浠€涔堟槸瀹忎换鍔″拰寰换鍔★紵棣栧厛锛屾垜浠渶瑕佸厛浜嗚ВJs銆俲s鏄竴绉嶅崟绾跨▼璇█锛岀畝鍗曠殑璇达細鍙湁涓€涓€氶亾锛岄偅涔堝湪浠诲姟澶氱殑鎯呭喌涓嬶紝灏变細鍑虹幇鎷ュ牭锛岃繖绉嶆儏鍐典笅灏变骇鐢熶簡鈥滃绾跨▼鈥濓紝浣嗘槸杩欎釜鈥滃绾跨▼鈥濇ā浠跨殑鏄崟绾跨▼锛岃繖鏄亣鐨勩€傜劧鍚庢湁鍚屾浠诲姟鍜屽紓姝ヤ换鍔°€?.涓轰粈涔圝S瑕佸尯鍒嗗畯浠诲姟鍜屽井浠诲姟锛燂紙1锛塉S鏄崟绾跨▼鐨勶紝浣嗘槸鍒嗗悓姝ュ拰寮傛\(2)寰换鍔″拰瀹忎换鍔￠兘鏄紓姝ヤ换鍔★紝閮藉睘浜庝竴涓槦鍒梊(3)瀹忎换鍔′竴鑸槸锛歴cript,setTimeout,setInterval,postMessage,MessageChannel,setImmediate(Node.js鐜)\(4)microtasks:Promise.then,Object.observe,MutationObserver,process.nextTick(Node.js鐜)\(5)鍏堝悓姝ユ墽琛屽啀寮傛锛屽紓姝ラ亣鍒癿icrotasks鍏堟墽琛宮icrotasks锛屾墽琛屽畬鍚庯紝濡傛灉鏈夋病鏈夊井浠诲姟锛屾墽琛屼笅涓€涓畯浠诲姟銆傚鏋滄湁microtasks锛屾寜椤哄簭涓€涓竴涓墽琛宮icrotasks銆備粈涔堟槸寰换鍔★紵瀹忎换鍔′竴鑸湁锛歴cript銆乻etTimeout銆乻etInterval銆乸ostMessage銆丮essageChannel銆乻etImmediate锛圢ode.js鐜锛夊井浠诲姟锛歅romise.then銆丱bject.observe銆丮utationObserver銆乸rocess.nextTick锛圢ode.js鐜锛夊洓銆佸畯浠诲姟锛屽井浠诲姟浠诲姟鏄浣曟墽琛岀殑锛熸墽琛岄『搴忥細鍏堟墽琛屽悓姝ヤ唬鐮侊紝閬囧埌寮傛瀹忎换鍔℃椂灏嗗紓姝ュ畯浠诲姟鏀惧叆瀹忎换鍔￠槦鍒楋紝閬囧埌寮傛寰换鍔℃椂灏嗗紓姝ュ井浠诲姟鏀惧叆寰换鍔￠槦鍒楋紝褰撴墍鏈夊悓姝ヤ唬鐮侀兘鎵ц瀹屾墽琛屽畬鍚庯紝鍐嶅皢闃熷垪涓殑寮傛寰换鍔¤浆绉诲埌涓荤嚎绋嬩腑鎵ц锛岀瓑寰换鍔℃墽琛屽畬鍚庡啀灏嗛槦鍒椾腑鐨勫紓姝ュ畯浠诲姟杞Щ鍒颁富绾跨▼涓墽琛岋紝濡傛寰幆寰€澶嶏紝鐩村埌鎵€鏈変换鍔℃墽琛屽畬姣曘€傝繖閲屽緢瀹规槗浜х敓閿欒鐨勭悊瑙ｏ細鍗砿icrotasks鍏堜簬macrotasks鎵ц銆傚疄闄呬笂鏄厛鎵ц鍚屾浠诲姟锛屽啀鎵ц寮傛浠诲姟銆傚紓姝ヤ换鍔″垎涓哄畯浠诲姟鍜屽井浠诲姟銆傛渚?锛歴etTimeout(function(){console.log(1);});newPromise(function(resolve){console.log(2);resolve();}).then(function(){console.log(3);}).then(鍑芥暟(){console.log(4)});console.log(5);//25341鍒嗘瀽锛氶亣鍒皊etTimout锛屽紓姝ュ畯浠诲姟锛屾斁鍏ュ畯浠诲姟闃熷垪涓亣鍒版柊鐨凱romise鏃讹紝鏂扮殑Promise鍦ㄥ疄渚嬪寲杩囩▼涓墽琛岀殑浠ｇ爜鏄悓姝ョ殑锛屾墍浠ヨ緭鍑?Promise.then锛屼竴涓紓姝ュ井浠诲姟锛屾斁鍏ュ井浠诲姟闃熷垪涓亣鍒板悓姝ヤ换鍔℃帶鍒跺彴銆傛棩蹇楋紙5锛夛紱杈撳嚭5锛涗富绾跨▼涓殑鍚屾浠诲姟鎵ц瀹屾瘯锛屼粠microtask闃熷垪涓彇鍑轰换鍔″埌涓荤嚎绋嬶紝杈撳嚭3銆?锛宮icrotask闃熷垪涓虹┖锛屼粠macrotask闃熷垪涓彇鍑轰换鍔″埌涓荤嚎绋嬶紝杈撳嚭1銆傚畯浠诲姟闃熷垪涓虹┖绀轰緥2锛歴etTimeout(()=>{newPromise(resolve=>{resolve();}).then(()=>{console.log('test');});console.log(4);});newPromise(resolve=>{resolve();console.log(1)}).then(()=>{console.log(3);Promise.resolve().then(()=>{console.log('瓒呮椂鍓?);}).then(()=>{Promise.resolve().then(()=>{console.log('涔熷湪瓒呮椂鍓?)})})})console.log(2);//1,2,3,瓒呮椂鍓?涔熸槸瓒呮椂鍓?4,t缇庝笢鏃堕棿;鍒嗘瀽锛氶亣鍒皊etTimeout锛屽紓姝ュ畯浠诲姟锛屽皢()=>{console.log(4)}鏀惧叆瀹忎换鍔￠槦鍒楋紱閬囧埌newPromise锛宯ewPromise鍦ㄥ疄渚嬪寲鏃舵墽琛岀殑浠ｇ爜鏄悓姝ユ墽琛岀殑锛屾墍浠ヨ緭鍑?锛涜€孭romise.then锛屼竴涓紓姝ュ井浠诲姟锛屾斁鍏ュ井浠诲姟闃熷垪锛岄亣鍒颁竴涓悓姝ヤ换鍔onsole.log(2)锛岃緭鍑?锛涗富绾跨▼涓殑鍚屾浠诲姟鏄粠microtask涓墽琛岀殑浠庨槦鍒椾腑鍙栧嚭浠诲姟鍙戦€佺粰涓荤嚎绋嬶紝杈撳嚭3锛岃繖涓猰icrotask涓湁microtask锛孭romise.resolve().then(microtaska).then(microtaskb),渚濇鏀惧叆microtask闃熷垪锛涗粠microtask闃熷垪涓彇鍑簍aska鍒颁富绾跨▼锛岃秴鏃跺墠杈撳嚭锛涗粠寰换鍔￠槦鍒椾腑鍙栧嚭浠诲姟b鍒颁富绾跨▼锛屼换鍔娉ㄥ唽涓€涓井浠诲姟c鏀惧叆寰换鍔￠槦鍒楋紱浠庝换鍔￠槦鍒椾腑鍙栧嚭浠诲姟c鍒颁富绾跨▼锛岃秴鏃跺墠涔熻緭鍑猴紱microtask闃熷垪涓虹┖锛屼粠macrotask闃熷垪涓彇task鍒颁富绾跨▼锛屽湪杩欎釜task涓敞鍐屼竴涓猰icrotaskd锛屾斁鍏icrotaskqueue涓紝鐒跺悗閬囧埌杈撳嚭4锛宮acrotask闃熷垪涓虹┖锛屼粠microtask涓彇taskd闃熷垪鍒颁富绾跨▼锛岃緭鍑烘祴璇曪紝寰换鍔￠槦鍒椾负绌虹ず渚?锛歝onsole.log(1)setTimeout(function(){console.log(1)setTimeout(function(){console.log(2)},0)constp=newPromise((resolve,reject)=>{resolve(4)})p.then(data=>{console.log(data)})console.log(3)//1,3,4锛?鍒嗘瀽锛氶亣鍒板悓姝ヤ换鍔onsole.log(1);杈撳嚭1锛涢亣鍒皊etTimeout寮傛瀹忎换鍔★紝鏀惧叆瀹忎换鍔￠槦鍒楋紱閬囧埌Promise锛宯ewPromise鍦ㄥ疄渚嬪寲杩囩▼涓殑浠ｇ爜executedin閮芥槸鍚屾鐨勶紝浣嗘槸鐢变簬newPromise涓嶈緭鍑轰簨浠讹紝鎵€浠ュ悗缁墽琛岄亣鍒?then锛?then鐨勬墽琛岋紝寮傛寰换鍔★紝鍒嗗彂缁欏井浠诲姟Eve闃熷垪锛涢亣鍒板悓姝ヤ换鍔℃帶鍒跺彴銆傛棩蹇楋紙3锛夛紱杈撳嚭3锛涗富绾跨▼涓殑鍚屾浠诲姟鎵ц瀹屽悗锛屼粠microtask闃熷垪涓彇鍑轰换鍔″埌涓荤嚎绋嬶紝p.then杈撳嚭4锛宮icrotask鎵ц瀹屾瘯锛屼换鍔￠槦鍒椾负绌猴紱寮€濮嬫墽琛屽畯浠诲姟setTimeout杈撳嚭2.瀹忎换鍔￠槦鍒椾负绌猴紱绀轰緥4锛氭帶鍒跺彴銆俵og(1)setTimeout(function(){console.log(2)newPromise(function(resolve){console.log(3)resolve()}).then(function(){console.log(4)})})newPromise(function(resolve){console.log(5)resolve()}).then(function(){console.log(6)})setTimeout(function(){console.log(7)newPromise(function(resolve){console.log(8)resolve()}).then(function(){console.log(9)})})console.log(10)//1,5,10,6,2銆?銆?銆?銆?銆?鍒嗘瀽锛氶亣鍒板悓姝ヤ换鍔onsole.log(1)鏃讹紱杈撳嚭1锛涢亣鍒皊etTimeout寮傛瀹忎换鍔★紝鏀惧叆瀹忎换鍔￠槦鍒楋紱閬囧埌Promise锛宯ewPromise鍦ㄥ疄渚嬪寲杩囩▼涓墽琛岀殑浠ｇ爜鏄悓姝ョ殑锛屾墍浠ヨ緭鍑烘槸5锛屾墍浠ユ墽琛岄亣鍒?then锛?then鐨勬墽琛岋紝寮傛寰换鍔★紝琚垎鍙戝埌寰换鍔′簨浠堕槦鍒楋紱閬囧埌setTimeout锛屽紓姝acrotask锛涙斁鍏ュ畯浠诲姟闃熷垪锛涢亣鍒颁竴涓悓姝ヤ换鍔onsole.log(10)锛涜緭鍑?0锛屼富绾跨▼涓殑鍚屾浠诲姟鍏ㄩ儴鎵ц瀹屾瘯锛涗粠寰换鍔￠槦鍒椾腑鍙栦换鍔″埌涓荤嚎绋嬶紝杈撳嚭6锛涘湪浠庡畯浠诲姟闃熷垪涓彇鍑轰换鍔＄粰涓荤嚎绋嬶紝鎵ц绗竴涓猻etTimeout锛岃緭鍑?銆?銆?锛堝湪瀹忎换鍔′腑鎵ц鍚屾銆佸悓姝ャ€佸紓姝ュ井浠诲姟锛夛紱鎵ц绗簩娆etTimeout锛岃緭鍑?銆?銆?锛堝拰8锛夛紱绀轰緥5锛歯ewPromise((resolve,reject)=>{resolve(1)newPromise((resolve,reject)=>{resolve(2)}).then(data=>{console.log(data)})}).then(data=>{console.log(data)})console.log(3)//3銆?銆?鍒嗘瀽锛氶亣鍒癙romise锛屽疄渚嬪寲newPromise鎵ц鐨勪唬鐮乮n鐨勬祦绋嬮兘鏄悓姝ョ殑锛屼絾鏄洜涓烘柊鐨凱romise娌℃湁杈撳嚭浜嬩欢锛屾墍浠ュ綋涓嬩竴娆℃墽琛岄亣鍒版柊鐨凱romise娌℃湁杈撳嚭浜嬩欢锛岄偅涔堜笅涓€娆℃墽琛岄亣鍒?then锛屼竴涓紓姝ュ井浠诲姟锛屽垎鍙戠粰寰换鍔″湪浠诲姟EventQueue涓紝鐒跺悗灏?then鏀惧叆microtask涓紝閬囧埌鍚屾浠诲姟console.log(3)杈撳嚭3锛屼富绾跨▼涓殑鍚屾浠诲姟琚墽琛岋紱浠巑icrotask闃熷垪涓彇浠诲姟鍒颁富绾跨▼锛岃緭鍑?,1锛宮icrotask鎵ц瀹屾瘯锛屼换鍔￠槦鍒椾负绌恒€傛€荤粨microtasks鍜宮acrotasks鐨勬墽琛岄『搴忔槸鍏堟墽琛屽悓姝ヤ换鍔★紝鍐嶆墽琛屽紓姝ヤ换鍔°€?濡傛灉鎵ц鍚庢病鏈塵icrotask锛屽垯鎵ц涓嬩竴涓猰acrotask銆傛湰鏂囬鍙戜簬鎺橀噾骞冲彴銆傛渶鍚庢劅璋㈠ぇ瀹堕槄璇烩瓙锔忊瓙锔忊瓙锔忋€傚鏋滀綘鍠滄瀹冿紝瀹冨浣犱篃鏈夊府鍔┿€傛杩庣偣璧炵暀瑷€馃挄馃挄馃挄
