按前2个字母分组或列出单词

Question

I'd like to list/group words by the first two letters but I can't get my head around it. I guess I can I can do a substr() and check against while looping but I'm not sure if this is the way to do it.

Something like:

if (substr($word, 0, 2) == 'aa') {
 echo $word;
}

What I'm trying to achieve: Words get sorted first by their starting letter, eg A, B, C etc. On the A page you have the words sorted by the first 2 letters, eg aa, ab, ac etc.

An example for this is http://www.urbandictionary.com/browse.php?word=aa . They do exactly what I'm after.

Help/thoughts appreciated!

Answer 1

If you have a bunch of words, put them grouped together in an array.

for example:

<?php
$myWords = array ("hello", "hell", "ape", "word", "appel");
$myGroupedArr = array();
foreach ($myWords as $oneWord){
  $firstTwo = substr($oneWord,0,2);
  $myGroupedArr[$firstTwo][] = $oneWord;  
}
echo "<pre>";
print_r($myGroupedArr);
echo "</pre>";
?>

Answer 2

I would sort not only by the first letter, but by the whole word, or at least by the first two letters.

Then, you can indeed use substr to get the first two letters of the first word. You can then enter the loop, and check the first two letters of the word in the loop, with the two letters you got before.

If they differ, you know you got a new group. You can echo a group header and store the new to letters to compare with in the following iterations.

// Words in a sorted array.
$words = array( ...... );
asort($words);

$currentGroup = '';
foreach ($words as $word)
{
    $newGroup = substr($word, 0, 2);

    if ($newGroup !== $currentGroup)
    {
        // A new group is starting.
        echo "=== $newGroup ===<br/>";
        $currentGroup = $newGroup;
    }

    echo $word . '<br/>';
}