var achearr=[1,2,3,4];
var bchearr=[];
//方法1:
for (var i = 0; i <=achearr.length;i++) {
bchearr.push(achearr.pop());
}
bchearr.push(achearr[0]);
console.log(bchearr)

 //方法2:
for (var i = 0; i <= achearr.length; i++) {
var a=i;
var b=i+1;
bchearr.sort(function (a, b) {
return a- b
})
}
console.log(bchearr)