## 迭代器函數 ~~~ function makeIterator(arr){ let nextIndex = 0; //返回一個迭代器對象 return { next:()=>{ //next()方法返回的結果為對象 if(nextIndex<arr.length){ return {value:arr[nextIndex++],done:false} }else{ return {done:true} } } } } var arr=['吃飯','睡覺','工作'] var it = makeIterator(arr); console.log(it.next()); console.log(it.next()); console.log(it.next()); console.log(it.next()); ~~~ ## generator生成器 ~~~ function *generator(arr){ for(let i =0;i<arr.length;i++){ yield arr[i] } } var gen = generator(['吃飯','睡覺','工作']); console.log(gen.next()) console.log(gen.next()) console.log(gen.next()) console.log(gen.next()) ~~~ ~~~ //執行結果 {value: "吃飯", done: false} {value: "睡覺", done: false} {value: "工作", done: false} {value: undefined, done: true} ~~~