var arrDemo = new Array(); arrDemo[0] = 10; arrDemo[1] = 50; arrDemo[2] = 51; arrDemo[3] = 100; arrDemo.sort(); //调用sort方法后,数组本身会被改变,即影响原数组 alert(arrDemo);//10,100,50,51 默认情况下sort方法是按ascii字母顺序排序的,而非我们认为是按数字大小排序 arrDemo.sort(function(a,b){return a>b?1:-1});//从小到大排序 alert(arrDemo);//10,50,51,100 arrDemo.sort(function(a,b){return a<b?1:-1});//从大到小排序 alert(arrDemo);//100,51,50,10