有人能告诉我为什么这段代码会无限循环吗？

Question

it is supposed to increment every other element in an array but when I run it it goes to infinite loop.

function incrementSecond(arr){
 for (var i = 0; i < arr.length; i + 2){
  arr[i] += 1;
  console.log(arr[i]);
 }
 return arr;
};
console.log(incrementSecond([1,2,3,4]));

Answer 1

你应该做的：

 for (var i = 0; i < arr.length; i = i + 2) {

将 i + 2 更改为 i = i + 2 或 i += 2。