JavaScript-数组遍历

什么是数组的遍历

数组的遍历就是依次取出数组中存储的所有数据, 我们就称之为数组的遍历。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Demo</title>
    <script type="text/javascript">
        let arr = ["a", "b", "c"];
        
        console.log(arr[0]);
        console.log(arr[1]);
        console.log(arr[2]);
    </script>
</head>
<body>
</body>
</html>

紧接着再往数组当中添加两个元素，可以调用一个 length 方法获取数组的元素长度

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Demo</title>
    <script type="text/javascript">
        let arr = ["a", "b", "c"];

        console.log(arr[0]);
        console.log(arr[1]);
        console.log(arr[2]);

        arr[3] = "d";
        arr[4] = "f";

        console.log(arr.length);
    </script>
</head>
<body>
</body>
</html>

有了长度之后就可以利用循环来进行数组的遍历了

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Demo</title>
    <script type="text/javascript">
        let arr = ["a", "b", "c"];

        console.log(arr[0]);
        console.log(arr[1]);
        console.log(arr[2]);

        arr[3] = "d";
        arr[4] = "f";

        for (let i = 0; i < arr.length; i++) {
            console.log(arr[i]);
        }
    </script>
</head>
<body>
</body>
</html>

posted @ 2021-06-30 11:30  BNTang  阅读(238)  评论(0)  编辑  收藏  举报