利用map reduce方法将对象转成数组

map 操作
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    <title>利用map reduce将对象转为数组并且拉平</title>
</head>
<body>
    <script>
        var keys = ['a','b','c']
        //js Map 方法
        var dataObj = {
            a:[1],
            b:[2],
            c:[3,5]
        }
        console.log(keys.map(key => dataObj[key]))//[[1],[2],[3,5]]
        var result = keys.map(key => dataObj[key])
            .reduce((prev,next) => prev.concat(next),[])
        console.log(result)  //[1,2,3,5]
    </script>
</body>
</html>