map 数组

<!DOCTYPE html>
<html lang="en">

<body>
    <script>
        var data = [1, 2, 3, 4, 5];
        var arr = data.map(function(val) {
            //数组中幂的运算
            return Math.pow(val, 3)
        });
        document.write(arr)
        document.write("<br/>")
        var qq = ['A', 'B', 'C', 'D']
        var zzz = qq.map(function(val) {
            //数组中的大写换小写
            return val.toLocaleLowerCase()
        })
        document.write(zzz)

</script>
</body>