// 方法1 使用sort 方法

         var  arr = [1,2,3,4,5,6,7,8];

         function foo(arr) {

             var cloneArr = arr.concat();

             cloneArr.sort(function (n1,n2) {

                 return Math.random() - 0.5 ;

             });

             return cloneArr;

         }

         for (var i= 0 ; i < arr.length ; i++ ){

             console.log(foo(arr));

         }

    <script>

        var arr = [1,2,3,4,5,6,7,8];

        function foo(arr) {

            //使用concat 复制一个数组中

            var  cloneArr = arr.concat();

            var result = [];

                (function name(params) {

                    if (!cloneArr.length)  return ;

                    var index = Math.floor(Math.random() * cloneArr.length);

                    result = result.concat(cloneArr.splice(index, 1));

                    arguments.callee();

                })()

            return result;

        }

        for (let i = 0; i < arr.length; i++) {

            console.log(foo(arr))

        }

    </script>

</html>

       var arr = [1, 2, 3, 4, 5, 6, 7, 8];

            function foo(arr) {

                //使用concat 复制一个数组中

                var cloneArr = arr.concat();

                var result = [];

                var len = cloneArr.length;

                for(var i= 0 ;i< len ;i++){

                    var index = Math.floor(Math.random()* cloneArr.length);

                    result = result.concat(cloneArr.splice(index,1));

                }

                return result ;

            }

            for (let i = 0; i < arr.length; i++) {

                console.log(foo(arr))

            }

                   var arr = [1, 2, 3, 4, 5, 6, 7, 8];

                    function foo(arr) {

                        //使用concat 复制一个数组中

                        var cloneArr = arr.concat();

                        for (var i = 0; i < cloneArr.length; i++) {

                            var index = Math.floor(Math.random() * cloneArr.length);

                            var temp = cloneArr[index];

                            cloneArr[index] = cloneArr[i];

                            cloneArr[i] = temp;

                        }

                        return cloneArr;

                    }

                    for (let i = 0; i < arr.length; i++) {

                        console.log(foo(arr))

                    }