使用PHP foreach的多个循环？

Question

$result contains an array of data items from a database query.

$A is an empty array. I also have created an empty array called $B and so on.

I want to loop through all 26 letters of the alphabet. For each letter I want to loop through the array containing my database query results and push them onto their respective array. So 'Ant' and 'Antelope' get pushed onto array $A, 'Buffalo' onto array $B and so on.

Here's my problem PHP:

$letter = 'A';
  for($count = 1; $count <= 26; ++$count) {
    foreach ($result as $topic) {
      if (substr($topic->animal, 0, 1) == $letter //the first letter is A, B...
        array_push($A, $topic->animal);
      }
    }
  }
  $letter++;
}

1. I think the internal array pointer is being moved to the end of $result because I only get animals starting with the letter A being pushed onto array $A. All other arrays ($B, $C etc.) are empty. In any case it only works once (for the letter A). reset($result) doesn't seem to work. How can I loop through $result multiple (26) times?

2. How do I change the array to be pushed onto when looping through the letters? In other words when $letter is incremented to B I want: array_push($B, $topic->animal);

Thanks in advance.

Answer 1

1. You are always pushing onto A, so it makes sense that it won't affect any other array.
2. You can use array_push($$letter,$topic->animal); (Variable variables) but it's not recommended - you should use a nested array insted with array_push($letters[$letter],$topic->animal)

That said, try this:

$letters = Array();
foreach($result as $topic) {
    $letters[substr($topic->animal,0,1)][] = $topic->animal;
}