js甯哥敤鏂规硶闆嗗悎reducereduce()閬嶅巻褰撳墠鏁扮粍锛屽唴缃洖璋冨嚱鏁帮紝閫氳繃鍙傛暟鑾峰彇precur瀹氫箟鍒濆€肩瓑锛岃繑鍥炰换鎰忎綘鎯宠繑鍥炵殑鍊?pre:鑾峰彇涓婁竴杞繑鍥炵殑缁撴灉cur:鑾峰彇褰撳墠閬嶅巻鐨勫厓绱燾onstarray1=[1,2,3,4];//0+1+2+3+4constinitialValue=0;constsumWithInitial=鏁扮粍1銆俽educe((previousValue,currentValue)=>{returnpreviousValue+currentValue},initialValue);console.log(sumWithInitial);//棰勬湡杈撳嚭锛?0constarr=[{age:12,sex:'鐢?,name:'灏忔槑',},{age:10,sex:'濂?,name:'灏忕孩',},{age:9,sex:'濂?,name:'灏忚姳',},]arr.reduce((prev,cur)=>{return{...prev,[`Student_${cur.name}`]:cur.sex,};},{})//棰勬湡杈撳嚭锛歿Student_XiaoMing:"Male"Student_Xiaohong:"Female"Student_Xiaohua:"Female"}瀹樻柟瑙ｉ噴reduce鏄墽琛屾瘡涓厓绱犳暟缁勯『搴忋€傚洖璋冨嚱鏁版帴鍙楀洓涓弬鏁帮細accumulatorcurrentValue褰撳墠鍊糲urrentIndex褰撳墠绱㈠紩鏁扮粍array[0,1,2,3,4].reduce(function(accumulator,currentValue,currentIndex,array){returnaccumulator+currentValue;});[0,1,2,3,4].reduce((绱姞鍣?currentValue,currentIndex,array)=>{returnaccumulator+currentValue},10)tips:閫氬父鎻愪緵鍒濆鍊兼洿瀹夊叏銆傚鏋滄彁渚涗簡initialValue锛屽畠浠庣储寮?寮€濮嬨€傚鏋滄病鏈夋彁渚沬nitialValue锛宺educe灏嗕粠绱㈠紩1寮€濮嬫墽琛屽洖璋冩柟娉曪紝璺宠繃绗竴涓储寮曘€傚鏋滄暟缁勫彧鏈変竴涓厓绱狅紝骞朵笖娌℃湁鎻愪緵initialValue锛屽垯杩斿洖鍞竴鍊硷紝涓嶆墽琛屽洖璋冦€傚啀鐪嬪嚑涓煂皏arflattened=[[0,1],[2,3],[4,5]].reduce(function(a,b){returna.concat(b);},[]);//鎵佸钩鍖栦负[0,1,2,3,4,5]varinitialValue=0;varsum=[{x:1},{x:2},{x:3}].reduce((绱姞鍣?currentValue)=>绱姞鍣?currentValue.x,initialValue);console.log(sum)//logs6assignassign鎺ュ彈涓や釜鍙傛暟锛岀洰鏍囧璞″拰婧愬璞°€傚鏋滅洰鏍囧璞′腑鐨勫睘鎬у叿鏈夌浉鍚岀殑閿紝鍒欒灞炴€у皢琚簮瀵硅薄涓殑灞炴€ц鐩朿onsttarget={a:1,b:2};const鏉ユ簮={b:4,c:5};constreturnedTarget=Object.assign(target,source);//source鍙細灏嗘簮瀵硅薄鏈韩鐨勫彲鏋氫妇灞炴€у鍒跺埌鐩爣瀵硅薄console.log(target);//棰勬湡杈撳嚭锛歄bject{a:1,b:4,c:5}console.log(returnedTarget);//棰勬湡杈撳嚭锛歄bject{a:1,b:4,c:5}console.log(source)//棰勬湡杈撳嚭锛歄bject{b:4,c:5}tips:褰撴簮瀵硅薄鐨勫€间负null鎴杣ndefined鏃讹紝Object.assign涓嶄細鎶涘嚭閿欒
