給數組大小做個排序

let value = [1,29999,399,6,488,8];
//小到大排序,如果需要由大到小,把返回的-1和1反過來就可以了
let arr = (x,y) => {
if(x < y){
return 1
}else if(x > y){
return -1;
}else{
return 0;
}
}
value.sort(arr)
 [29999, 488, 399, 8, 6, 1]