Dictionary.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>

</body>
<script>
    // 获取数量 
    /* 因为数组 key 为字符串时 长度失效 */
    function count() {
        var n = 0;
        for (var key in Object.keys(this.datastore)) {
            n++;
        }
        return n;
    }

    // 清空
    function clear() {
        for(var key in Object.keys(this.datastore)){
            delete this.datastore[key];
        }
    }

    // 添加
    function add(key, value) {
        this.datastore[key] = value;
    }

    // 寻找
    function find(key) {
        return this.datastore[key]

    }

    // 移除
    function remove(key) {
        delete this.datastore[key]
    }

    // 展示全部
    function showAll() {
        Object.keys(this.datastore).forEach((key) => {
            console.log(key, this.datastore[key]);
        })
    }

    // 字典构造
    function Dictionary() {
        this.datastore = new Array();
        this.add = add;
        this.find = find;
        this.remove = remove;
        this.showAll = showAll;
        this.count = count;
        this.clear = clear;
    }

    var pBook = new Dictionary();
    pBook.add('Mike', '18');
    pBook.add('Kevin', '20');
    pBook.add('Sani', '17');
    pBook.showAll();
    var count = pBook.count();

    
</script>

</html>