ES6基础知识（Set用法） 

<!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>Set</title>
</head>
<body>
    <script>
        var st = new Set([1,2,3,3]);//新建Set数据
        console.log(st);//自动清除重复项    Set {1, 2, 3}

        let obj = {'abc':111};
        st.add(obj);//添加
        console.log(st);//Set {1, 2, 3, Object {abc: 111}}
        // st.delete(obj);//删除
        // console.log(st); //Set {1, 2, 3} 

        for(let o of st){//遍历
            console.log(o);//1,2,3,Object {abc: 111}
        }

        let keysItem = st.keys();//获得key值
        console.log(keysItem);//SetIterator {1, 2, 3, Object {abc: 111}}

        let valuesItem = st.values();//获得value值
        console.log(valuesItem);//SetIterator {1, 2, 3, Object {abc: 111}}

        let entriesItem = st.entries();//获得key和value数组结构数据
        console.log(entriesItem);//SetIterator {[1, 1], [2, 2], [3, 3], [Object, Object]}

        st.clear();//清空Set数据
        console.log(st);//Set {}

    </script>
</body>
</html>

 备注：文中多数内容摘自阮一峰老师文章，仅供自我学习查阅。

posted @ 2019-02-16 09:47  周大侠小课堂  阅读(1418)  评论(0)  编辑  收藏  举报