为什么有条件时此for循环是无限循环？

Question

This function below is to create array slice and push is giving infinite loop. Can anybody try to justify that.

function MyFunction(arr, size) {
  var  newArr = [];

  for(var i=0; i<arr.length; i+size)    
   {  
    newArr.push(arr.slice(i,i+size));

   }  
  return newArr;
}

I am able to achieve my requirement with below while loop, although it seems almost similar.

function MyFunction(arr, size) {
  var  newArr = [];
  var i = 0;
  while(i < arr.length)    
  {      
    newArr.push(arr.slice(i,i+size));
    i = i + size;  
   }  
  return newArr;

}

Sample Input :- myFunction(["a", "b", "c", "d"], 2);

Sample Output :- [["a", "b"], ["c", "d"]]

Answer 1

I think i+size should be i += size or i = i + size .

In the first loop, you're never incrementing i .

EDIT

You may also want to change the body of the loop to match the while loop too.

Eg, putting it all together, this for loop should be the equivalent of your while loop:

for (var i = 0; i < arr.length; i += size) {
    newArr.push(arr.slice(i, i + size));
}

Answer 2

In your for loop you are never incrementing your variable i . That is it. i++ auto increments i but i+size doesn't.

it should be i=i+size or i+=size ;

Hope this helps.

Edit

Your for loop should be:-

function MyFunction(arr, size) {
  var  newArr = [];

  for(var i=0; i<arr.length; i = i+size)    
   {  
    newArr.push(arr.slice(0,size));

   }  
  return newArr;
}