Arrange an array by the first letter

Long time, no post
Here is a small PHP tips&tricks post : we have an array full of values, let’s say a country list (in this example the list is limited, we don’t want to see 190+ values).

PHP [Show Styled Code]:

Array
(
    [0] => Array
        (
            [0] => Afghanistan
            [name] => Afghanistan
            [1] => AF
            [code] => AF
        )

    [1] => Array
        (
            [0] => Albania
            [name] => Albania
            [1] => AL
            [code] => AL
        )

    [2] => Array
        (
            [0] => Algeria
            [name] => Algeria
            [1] => DZ
            [code] => DZ
        )

    [3] => Array
        (
            [0] => Bangladesh
            [name] => Bangladesh
            [1] => BD
            [code] => BD
        )

    [4] => Array
        (
            [0] => Barbados
            [name] => Barbados
            [1] => BB
            [code] => BB
        )

    [5] => Array
        (
            [0] => Belgium
            [name] => Belgium
            [1] => BE
            [code] => BE
        )

    [6] => Array
        (
            [0] => Brazil
            [name] => Brazil
            [1] => BR
            [code] => BR
        )

    [7] => Array
        (
            [0] => Cape Verde
            [name] => Cape Verde
            [1] => CV
            [code] => CV
        )

    [8] => Array
        (
            [0] => Cayman Islands
            [name] => Cayman Islands
            [1] => KY
            [code] => KY
        )
)

PHP [Show Plain Code]:

Array
(
    [0] => Array
        (
            [0] => Afghanistan
            [name] => Afghanistan
            [1] => AF
            [code] => AF
        )
 
    [1] => Array
        (
            [0] => Albania
            [name] => Albania
            [1] => AL
            [code] => AL
        )
 
    [2] => Array
        (
            [0] => Algeria
            [name] => Algeria
            [1] => DZ
            [code] => DZ
        )
 
  
    [3] => Array
        (
            [0] => Bangladesh
            [name] => Bangladesh
            [1] => BD
            [code] => BD
        )
 
    [4] => Array
        (
            [0] => Barbados
            [name] => Barbados
            [1] => BB
            [code] => BB
        )
 
   
    [5] => Array
        (
            [0] => Belgium
            [name] => Belgium
            [1] => BE
            [code] => BE
        )
 
 
    [6] => Array
        (
            [0] => Brazil
            [name] => Brazil
            [1] => BR
            [code] => BR
        )
 
 
    [7] => Array
        (
            [0] => Cape Verde
            [name] => Cape Verde
            [1] => CV
            [code] => CV
        )
 
    [8] => Array
        (
            [0] => Cayman Islands
            [name] => Cayman Islands
            [1] => KY
            [code] => KY
        )
) 

and we want to display like this

-A-

Afghanistan
Albania
Algeria

-B-

Bangladesh
Barbados
Belgium
Brazil

-C-

Cape Verde
Cayman Islands

, the right and easy way to do this would be to retain in a variable the first letter of the last country and in another variable the first letter of the current country. We compare them and if they are different we just output the first letter and then the name of the current country. All this in just few and simple to understand lines, right?

PHP [Show Styled Code]:

//try to do the A-Z list
$v = function to get your country list from a DB sorted by country name!;
$last_letter = '';
$current_letter = '';
for ($i=0;$i" . $current_letter . "

"; } print $v[$i]["name"] . ""; $last_letter = $current_letter; }

PHP [Show Plain Code]:

//try to do the A-Z list
$v = function to get your country list from a DB sorted by country name!;
$last_letter = '';
$current_letter = '';
for ($i=0;$i<count($v);$i++)
{
        $current_letter = substr($v[$i]["name"],0,1);
        if ($last_letter != $current_letter)
        {
                print "<div align=center>" . $current_letter . "</div>";
        }
        print $v[$i]["name"] . "<br />";
        $last_letter = $current_letter;
} 

I hope this will help someone

Revision
09.12.2007, 12:09 : added "sorted by country name!" comment in the php code example. Thanks to Dragos.

Posted in PHP Tips & Tricks.

5 comments

By Trimbitas Sorin – December 8, 2007

5 Responses

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Dragos says

Great idea. Don’t forget to mention the prerequisite that the $v array must be sorted (It looks like you’re pulling the results from a database, so you probably achieve that using the ORDER BY clause)

December 9, 2007, 9:11 am
Trimbitas Sorin says

Yes, indeed, it must be sorted in order to work as designed.
Thanks for the observation

December 9, 2007, 10:08 am
Wayne says

In your for loop you use a variable named ‘count’ as the value to test the $i counter variable, but you didn’t define the value of ‘count’. Is this an error, or does PHP reserve ‘count’ as a constant? If so, what is the value of ‘count’?

April 25, 2008, 5:02 am
Trimbitas Sorin says

Wayne … count is a prebuild function that returns the number of elements of an array.
Hope this helps

April 25, 2008, 8:41 am
Gulde says

Wow, cool tutorial, it really helped me a lot, it was precisly what i was looking for (^^)b

Thanks a lot

November 17, 2008, 4:23 pm