Question

I have an array with terms and definitions:

$myArray = array("apple" => "Fruit that grows ...", "car" => "Vehicle on four...");  

How do I determine if I have words starting with a particular letter in $myArray, say, “c” for car and add a class to corresponding letter in my ABC list that is generated via a loop:

foreach(range('A','Z') as $i) {
    echo '<div>'. $i .'</div>';
}

UPDATE:

Expected output:

<div class="match">A</div>
<div>B</div>
<div class="match">C</div>

Answer 1

You need to compare whether the character you are about to output does exist as a first character in the array keys. Compared with all the other working solutions, which iterate over the whole data array over and over again, using a little preparation should make it easier and more understandable what happens.

$myArray = array("apple" => "Fruit that grows ...", "car" => "Vehicle on four...", "cat" => "Meow");

// Prepare array keys
$keys = array_keys($myArray);
array_walk($keys, function(&$key){$key=mb_strtoupper(mb_substr($key,0,1));});
array_unique($keys);

foreach (range('A','Z') as $char) {
    if (in_array($char, $keys)) {
        echo "<div class='match'>".$char."</div>";
    } else {
        echo "<div>".$char."</div>";
    }
}

Output:

<div class='match'>A</div><div>B</div><div class='match'>C</div><div>D</div><div>E</div><div>F</div> ...