选择排序

<input type="button" onclick="go()" value="点击">
    <h3 id="chu"></h3>


    <script>
        var d = [3, 9, 4, 2, 6, 8, 7, 1, 99, 9, 9, 9];
        function xuanze(arr) {
            var index;
            // 循环到数组倒数第二个数结束
            for (var a = 0; a < arr.length - 1; a++) {

                index = a;

                for (var b = a + 1 ; b < arr.length; b++) {
                    // 对比，更改索引             
                    if (arr[b] < arr[index]) {
                        index = b;                      
                    }
                }
                // 交换位置
                [arr[index], arr[a]] = [arr[a], arr[index]];                  
            }           
            return arr;
        }

        function go() {
            document.getElementById('chu').innerHTML = xuanze(d);
        }
    </script>