var array = [1,2,3,4,5]; // ---> 服务//效率 ---> 针对一个有序的数组 效率最高//标志 true false for(var j = 0; j < array.length - 1;j++ ){//- j 每次排序完成之后 后面减少比较的次数var isTrue = true; //如果数组本身就是升序，则直接输出for(var i = 0; i < array.length - j - 1;i++){if(array[i] > array[i+1]){var temp = array[i];array[i] = array[i+1];array[i+1] = temp;isTrue = false;}}document.write(array);if(isTrue){break;}}

var array = [12,34,4,6,20];//length - 1 j = 0 - length - 1for(var j = 0; j < array.length - 1;j++){var min = array[j]; // 1 3 34 4 345 5var minIndex = j;for(var i = j + 1; i < array.length;i++){if(array[i] < min){min = array[i];minIndex = i;}}if(minIndex != j){var temp = array[minIndex];array[minIndex] = array[j];array[j] = temp;}}

<script type="text/javascript">    var a;    a = [66, 53, 11, 5, 4, 3, 2, 1];    /*冒泡排序*/    (function maopaopaixu() {      for (var i = 0; i < a.length - 1; i++) {//比较的次数是length-1        for (var j = 0; j < a.length - 1 - i; j++) {          if (a[j] > a[j + 1]) {            var tmp = a[j];            a[j] = a[j + 1];            a[j + 1] = tmp;          }        }      }      alert(a);    })();    a = [66, 53, 11, 5, 4, 3, 2, 1];    /*选择排序*/    (function xuanzepaixu() {      var min/*最小项的索引*/, tmp;      for (var out = 0; out < a.length - 1; out++) {//比较的次数是length-1        min = out;        for (var inner = out + 1; inner < a.length; inner++) {//这里是a.length，不是a.lenght-1，因为后者会导致右数第2项没法参与排序。          if (a[inner] < a[min]) {            min = inner;          }          //将最小的项移动到左侧          tmp = a[out];          a[out] = a[min]          a[min] = tmp;        }      }      alert(a);    })();    a = [66, 53, 11, 5, 4, 3, 2, 1];    /*插入排序*/    (function charupaixu() {      for (var out = 1; out < a.length; out++) {        var tmp = a[out];        var inner = out;        while (a[inner - 1] > tmp) {          a[inner] = a[inner - 1];          --inner;        }        a[inner] = tmp;      }      alert(a);    })();  </script>