title: In a 2d array. Iterate for the first 2 rows and 2 columns, then first 2 rows again, next 2 columns etc
body: <p>I am trying to iterate over an array in a weird way. I can't think of a good way to do it. I need iterate over the first 2 rows for just 2 columns at a time. So 4 index positions at a time. I would continue on the 1st 2 rows until out of columns then continue to the next 2 rows. I would do this until I was out of rows. I can assume the array will always be an even number of rows and columns (2, 4 , 6) , but not that they are square. It can end up being 4x6 etc. Also the smallest array possible will be a 4x4.</p>
  
  <p>Any suggestions? I am drawing a blank besides just hard coding it of sorts. Find the length of a row, divide it by 2, then just iterate that many times?</p>
  
  <p>Example: I have a 2d array. It is 4X4. That is 4, four element square 'blocks". Blocks are 2x2. So the first block I need to manipulate first is at index positions [0][0],[0][1],[1][0],[1][1]. </p>