16.迭代器自定義遍歷資料
阿新 • • 發佈：2022-01-02
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
</head>
<body>
<script>
const className = {
name: "三年一班",
students: ["小明", "小花", "小亮", "小王", "小李"],
[Symbol.iterator]() {
// 建立索引值
let index = 0;
// 儲存this
let that = this;
return {
next: function () {
//這裡也可以直接寫今天函式,沒有this指向問題
if (index < that.students.length) {
const result = { value: that.students[index], done: false };
// 索引值自增
index++;
return result;
} else {
return { value: undefined, done: true };
}
},
};
},
};
// for (const iterator of className.studets) { // console.log(iterator); // }
for (const v of className) { console.log(v); } </script> </body> </html>
// for (const iterator of className.studets) { // console.log(iterator); // }
for (const v of className) { console.log(v); } </script> </body> </html>