Given a (m x n) 2d array count the number of 5's in it.

Script
function count5s(arr) {
  var count = 0;
  // Loop through the array
  for (var i = 0; i < arr.length; i++) {
    // Check each row
    for (var j = 0; j < arr[i].length; j++) {
      // Check each value
      if (arr[i][j] === 5) {
        count++;
      }
    }
  }
  return count;
}

count5s([[1, 2, 5], [5, 5, 5], [5, 5, 5], [9, 5, 9]]);