鏉ヨ嚜绫诲瀷鍒ゆ柇鍦↗avaScript涓紝瀵瑰彉閲忚繘琛岀被鍨嬫牎楠屾槸涓€浠堕潪甯搁夯鐑︾殑浜嬫儏銆傚鏋滃崟绾殑浣跨敤typeof锛屽氨浼氶亣鍒板悇绉嶅悇鏍风殑闂銆傝繖閲屾湁鍑犱釜绠€鍗曠殑馃尠锛歝onsole.log(typeofnull)//'object'console.log(typeofnewArray)//'object'console.log(typeofnewString)//'object'鍚庢潵澶у鍙戠幇瀹冨彲浠ヤ娇鐢∣bject.prototype.toString()鏂规硶鏉ュ垽鏂彉閲忕被鍨嬨€俢onstgetTypeString=obj=>Object.prototype.toString.call(obj)getTypeString(null)//'[objectNull]'getTypeString('string')//'[objectString]'getTypeString(newString)//'[objectString]'浠ｇ悊toString()鏂规硶寰楀埌涓€涓瓧绗︿覆绫诲瀷锛屾垜浠彲浠ュ湪杩欎釜瀛楃涓蹭笂鍋氫竴浜涗簨鎯呫€俢onstgetTypeString=obj=>{returnObject.prototype.toString.call(obj)}constisType=type=>{returnobj=>{returngetTypeString(obj)===`[object${type}]`}}constisArray=isType('Array')//杩欎釜鏂规硶涓€鑸敤Array.isArray浠ｆ浛constisNull=isType('Null')constisObject=isType('Object')constisRegExp=isType('RegExp')constisFunction=isType('Function')constisAsyncFunction=isType('AsyncFunction')isNull(null)//trueisObject({})//trueisRegExp(/\w/)//trueisFunction(()=>{})//trueisAsyncFunction(async()=>{})//true浣嗘槸锛屽湪Node.js涓紝鍏跺疄鏈変竴濂楀垽鏂彉閲忕被鍨嬬殑API銆傝€屼笖鍔熻兘鏋佸叾涓板瘜銆傞櫎浜嗗熀鏈被鍨嬬殑鍒ゆ柇澶栵紝杩樻敮鎸佸Promise瀵硅薄銆丏ate瀵硅薄銆佸悇绉岮rrayBuffers鐨勫垽鏂€俢onsttypes=require('util/types')types.isDate(newDate)//truetypes.isPromise(newPromise(()=>{}))//truetypes.isArrayBuffer(newArrayBuffer(16))//true涓ユ牸鐩哥瓑鍦↗avaScript涓紝鍦ㄥ垽鏂璞°€佹暟缁勭瓑鍙橀噺鏄惁鐩哥瓑鐨勮繃绋嬩腑锛屽鏋滀娇鐢?==锛岄€氬父鍙細鍒ゆ柇涓や釜鍙橀噺鏄惁鎸囧悜鍚屼竴涓唴瀛樺湴鍧€銆傚鏋滆鍒ゆ柇瀵硅薄鐨刱ey瀵瑰簲鐨勬墍鏈夊€兼槸鍚︾浉绛夛紝闇€瑕侀亶鍘嗕袱涓璞°€倁til涓繕鎻愪緵浜嗗垽鏂袱涓璞℃槸鍚︿弗鏍肩浉绛夌殑鏂规硶锛?shenfq'}console.log('val1===val2',val1===val2)//falseconsole.log('isDeepStrictEqual',util.isDeepStrictEqual(val1,val2))//true杩欎釜鏂规硶鏄竴鏍风殑鍙互鐢ㄦ潵鍒ゆ柇鏁扮粍鏄惁涓ユ牸鐩哥瓑锛歝onstutil=require('util')constarr1=[1,3,5]constarr2=[1,3,5]console.log('arr1===arr2',arr1===arr2)//falseconsole.log('isDeepStrictEqual',util.isDeepStrictEqual(arr1,arr2))//trueErrorFirst&PromiseEarlyNodeAPIs閮芥槸ErrorFirst椋庢牸锛屽嵆鎵€鏈夌殑寮傛鍑芥暟閮戒細灏嗗畠鎺ュ彈涓€涓洖璋冨嚱鏁帮紝鍥炶皟鍑芥暟鐨勪竴涓弬鏁版槸閿欒瀵硅薄銆傚鏋滄甯歌繑鍥瀍rror瀵硅薄锛屽垯涓簄ull锛屽悗闈㈢殑鍙傛暟涓哄搷搴旀垚鍔熺殑缁撴灉銆?/涓嬮潰鏄竴涓鍙栨枃浠剁殑渚嬪瓙constfs=require('fs')fs.readFile('nginx.log',(error,data)=>{if(error){//璇诲彇鏂囦欢鎺у埗鍙板け璐?error(error)return}//璇诲彇鏂囦欢鎴愬姛骞舵墦鍗扮粨鏋渃onsole.log(data)})Node8鍙戝竷鏃讹紝澧炲姞浜嗕竴涓猵romisify鎺ュ彛锛岀敤浜庡皢ErrorFirst椋庢牸鐨凙PI杞崲涓篜romiseAPI銆俢onstfs=require('fs')constutil=require('util')constreadFile=util.promisify(fs.readFile)readFile('./2021-11-11.log',{缂栫爜:'utf-8'}).then(text=>console.log(text)).catch(error=>console.error(error))浣嗘槸鍚庢潵寰堝浜鸿寰楄繖浜涘師鐢烝PI鏀寔Promise鐨勬柟寮忓お绻佺悙浜嗭紝姣忎釜API閮芥槸闇€瑕佷竴灞傚崟鐙殑promisify鍖呰銆侼ode10鍙戝竷鏃讹紝鍘熺敓妯″潡澧炲姞浜嗕竴涓?promises灞炴€э紝璇ュ睘鎬т笅鐨勬墍鏈堿PI閮芥槸Promise椋庢牸鐨勩€俢onstfs=require('fs').promisesfs.readFile('./2021-11-11.log',{encoding:'utf-8'}).then(text=>console.log(text))銆俢atch(error=>console.error(error))娉ㄦ剰锛氬湪Node14涔嬪悗锛宲romisesAPI鏂板浜嗕竴涓鍏ユ柟娉曪紝閫氳繃淇敼鍖呭悕寮曞叆銆俢onstfs=require('fs/promises')fs.readFile('./2021-11-11.log',{encoding:'utf-8'}).then(text=>console.log(text)).catch(error=>console.error(error))闄や簡灏咵rrorFirst椋庢牸鐨凙PI杞崲涓篜romiseAPI澶栵紝util杩樻彁渚涗簡涓€涓猚allbackify鏂规硶灏哸sync鍑芥暟杞崲涓篍rrorFirst椋庢牸鐨勫嚱鏁般€備笅闈㈤€氳繃callbackify灏嗗熀浜巔romise鐨刦s鎭㈠涓篍rrorFirst椋庢牸鐨勫嚱鏁般€俢onstfs=require('fs/promises')constutil=require('util')constreadFile=util.callbackify(fs.readFile)readFile('./2021-11-12.log',{缂栫爜:'utf-8'},(error,text)=>{if(error){console.error(error)return}console.log(text)})璋冭瘯杈撳嚭濡傛灉寮€鍙戣繃Node鏈嶅姟锛屽簲璇ョ敤杩嘾ebugmodule锛岄€氳繃璇ユā鍧楀彲浠ュ湪鎺у埗鍙扮湅鍒版洿娓呮櫚鐨勮皟璇曚俊鎭€俢onstdebug=require('debug')constlog=debug('app')constuser={name:'shenfq'}log('currentuser:%o',user)鍏跺疄绫讳技鐨勪篃鍙互閫氳繃util瀹炵幇.debug鏁堟灉锛歝onstdebug=require('debug')constlog=debug('app')constuser={name:'shenfq'}log('currentuser:%o',user)鍙湪鍚姩鏃讹紝鎮ㄩ渶瑕佸皢DEBUG鐜鍙橀噺鏇挎崲涓篘ODE_DEBUG銆備粩缁嗙湅涓婇潰鐨勪唬鐮侊紝搴旇浼氬彂鐜板湪log('currentuser:%o',user)鏂规硶鍓嶉潰鐨勫瓧绗︿覆涓湁涓€涓?o鍗犱綅绗︼紝琛ㄧず杩欎釜鍦版柟浼氳涓€涓璞″～鍏咃紙鐩殑锛夈€傝繖绫讳技浜嶤鎴朠ython涓殑printf銆傚悓鏍凤紝鍦╱til妯″潡涓紝鐩存帴鎻愪緵浜嗕竴涓牸寮忓寲鏂规硶锛歶til.format銆俢onst{format}=require('util')console.log(format('currentuser:%o',{name:'shenfq',age:25}))闄?o鍗犱綅绗﹀锛屼笉鍚岀殑鏁版嵁绫诲瀷搴旇浣跨敤涓嶅悓鐨勫崰浣嶇銆傚崰浣嶇绫诲瀷%s瀛楃涓?d鏁板瓧锛堝寘鎷暣鏁板拰娴偣鏁帮級%i鏁存暟%f娴偣鏁?jJSON%oObjectJavaScript涓殑瀵硅薄鏄竴涓緢澶嶆潅鐨勪笢瑗匡紝闄や簡鐩存帴浣跨敤util.format澶栧姞%o鍗犱綅绗﹀璞′互绗﹀彿鐨勫舰寮忚繘琛屾牸寮忓寲锛寀til涔熸彁渚涗簡涓€涓柟娉曞彨inspect鏉ユ牸寮忓寲瀵硅薄銆俢onst{inspect}=require('util')constuser={age:25,name:'shenfq',work:{name:'coding',seniority:5}}console.log(inspect(user))鐪嬭捣鏉ュ儚杩欎釜inspect濂藉儚娌′粈涔堜綔鐢紝浣嗘槸inspect鏂规硶杩樻湁绗簩涓弬鏁帮紝鐢ㄦ潵鏍煎紡鍖栫殑鏃跺€欏仛涓€浜涗釜鎬у寲鐨勯厤缃€俤epth:number锛氭帶鍒舵樉绀哄眰娆★紱sorted:boolean|鍔熻兘锛氭槸鍚︽寜鐓ey鐨勭紪鐮佸€艰繘琛屾帓搴忥紱compact:boolean:鏄惁鍗曡鏄剧ず锛涘綋鐒讹紝浠ヤ笂鍙槸閮ㄥ垎閰嶇疆锛屾洿璇︾粏鐨勯厤缃彲浠ユ煡鐪媙ode鏂囨。銆傚啓鍑犱釜妗堜緥锛氭墍鏈夊睘鎬ф崲琛屾樉绀猴細inspect(user,{compact:false})鍙牸寮忓寲瀵硅薄绗竴灞傜殑鍊硷細inspect(user,{depth:0,compact:false})鏍规嵁閿€肩殑缂栫爜鍊掑簭杈撳嚭锛歩nspect(user,{compact:false,sorted:(a,b)=>a
