如何以字母顺序列出带有标题的项目，如果找不到匹配项，则显示一条消息

Question

My plan of action was:

1. Loop through an array of the alphabet
2. While inside of that loop, print the current letter
3. While inside of that loop cycle through a list of city objects stored in an array.
4. Check and see if the first letter of the $city->city_name property matches the current letter in the loop. If it matches, print it.
5. If there are no matches, print a message saying so.

This is all I can get it to display:

A

There are no results to display.

B

There are no results to display.

C

City

There are no results to display.

D

There are no results to display.

E

City

There are no results to display.

As you can see, the error displays even if there is a match. I cannot seem to figure out where the flaw in my logic is and I've searched through every question on the topic. Is there something obvious that I am missing?

Code:

<?php
function printValues($cities, $county) 
{
    $str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    $letters = str_split($str);
    $lettersMatched = FALSE;

    foreach ($letters as $letter) 
    {
        echo "<h5 class=\"letter\">".$letter."</h5><hr>";

        foreach ($cities as $city) 
        {
            if(substr($city->city_name, 0, 1) == $letter) 
            {
                $lettersMatched = TRUE;
                $result = $city->city_name;
                echo "<p><a href=\"".site_url("/listings/county/".$county."/city/".$result)."\">".$result."</a></p>";
                $lettersMatched = FALSE;
            }
        } 
        if (!$lettersMatched) 
        {
            echo "<p>There are no results to display.</p>";
        }
    }
}
?>

Answer 1

You're resetting $lettersMatched to false inside the if statement. Try this:

<?php
function printValues($cities, $county) 
{
    $str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    $letters = str_split($str);
    //$lettersMatched = FALSE;

    foreach ($letters as $letter) 
    {
        echo "<h5 class=\"letter\">".$letter."</h5><hr>";
        $lettersMatched = FALSE;

        foreach ($cities as $city) 
        {
            if(substr($city->city_name, 0, 1) == $letter) 
            {
                $lettersMatched = TRUE;
                $result = $city->city_name;
                echo "<p><a href=\"".site_url("/listings/county/".$county."/city/".$result)."\">".$result."</a></p>";
                // $lettersMatched = FALSE;
            }
        } 
        if (!$lettersMatched) 
        {
            echo "<p>There are no results to display.</p>";
        }
    }
}
?>

Answer 2

$matches = false;
foreach(range('A', 'Z') AS $letter)
{
    echo $letter . '<hr>';

    foreach( $cities AS $city )
    {
        if( strtoupper(substr($city->city_name, 0, 1)) ===  $letter)
        {
            $matches = true;
            echo "<p>" . $city->city_name . "</p>";
        }
    }

    if(!$matches)
        echo "<p>No matches here</p>";

    $matches = false;

}

What you did was to set the matches to false right after you set it to true in the inner loop. So when your code reaches the condition outside the loop it will always be false .

What I did was to set the matches to false after the condition, so it will be checked again for each new letter.