向后循环Javascript数组

var arr = [1, 2, 3, 4, 5];
var startIndex = 2; // 从索引2开始循环

for (var i = startIndex; i < arr.length + startIndex; i++) {
  var index = i % arr.length; // 取余操作，实现循环
  console.log(arr[index]);
}

var arr = [1, 2, 3, 4, 5];
var startIndex = 2; // 从索引2开始循环

arr.forEach(function(element, index) {
  var newIndex = (index + startIndex) % arr.length; // 取余操作，实现循环
  console.log(arr[newIndex]);
});