数组sort()方法排序

var arr = ["G","A","C","B","I","H","G","I","B"];
arr.sort();
console.log(arr);

var arr = [23,435,456,23,2,345,2,32,11,324,32,43,65,667,78,43];
arr.sort();
console.log(arr);

var arr = [23,435,456,23,2,345,2,32,11,324,32,43,65,667,78,43];
// 升序
arr.sort(function(a,b){
    //如果a要放在b前面，那么返回负数
    //如果a要放在b后面，那么返回正数
    //如果a和b不区分大小，那么返回0
    if(a < b){
        return -1;  //满足第一个条件，返回值是-1，a要排在b前面
    }else if(a > b){
        return 1;   //满足第二个条件，返回值是1，a要排在b后面
    }else if(a == b){
        return 0;
    }
});
console.log(arr);

//按五角星的个数排序
var arr = ["★★★","★★★★★","★★","★★★","★","★★★★★★★★","★★★","★★★★★"];
arr.sort(function(a,b){
    if(a.length > b.length){
        return -1;  //满足第一个条件，返回值是-1，a要排在b前面
    }else if(a.length < b.length){
        return 1;   //满足第二个条件，返回值是1，a要排在b后面
    }else{
        return 0;
    }
});
console.log(arr);