CODEWITHSUNDEEP
phpmysqlsql
Damian Doman
Damian Doman

Reputation: 532

PHP/MySQL - Incrementing variable name to loop for data

I have rows in my teams table named player1, player2, player3 ... player12. In PHP script i set them as variables ($player1,$player2...) and want to loop through them to check if they are NULL, and if they are not to count them.

How may I increment a variable in PHP? I have tried doing it likes this:

<?
    $playerspicked = 0;
    for($i = 1; $i <= 12; $i++) {
        $playercheck = "$player"+$i;
        if($playercheck != 0) {
            $playerspicked++;
        }
    }
?>

but this wouldn't work.

Upvotes: 1

Views: 331

Answers (2)

Clement Hamon
Clement Hamon

Reputation: 56

In your case there is a much easier way to count all the not null players in the team.

echo count(array_filter($yourTeam));

the array_filter function without a second parameter will automatically remove the null entries.

Upvotes: 1

GrumpyCrouton
GrumpyCrouton

Reputation: 8621

You can do this with complex expressions (curly brackets {}) around a variable name.

if(empty(${"player$i"})) {
    //player$i is empty
}

complex expressions allow you to set variable names dynamically.

To help you better understand how these work, I will show you that you can also use these just like regular string concatenation like so

$variable = "many test";
echo "this is a test echo. {$variable}";

I commonly use this for generating a variable for many array variables based on their key

$array = array("key1" => "value1", "key2" => "value2");
foreach($array as $key => $value) {
    ${$key} = $value;
}

The code above would create 2 variables, $key1 and $key2, with the appropriate value associated with them.

Alternatively, I'm pretty sure you can just add another $ to the front of your variable, but I would say this is harder to read and figure out what's going on.

$playercheck = "player"+$i;  
if($$playercheck != 0) {
    $playerspicked++;
}

Upvotes: 3

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