Matching pairs of game and event ID

Question

I was wondering if someone could give some tips as to how improve long strings of if-else statements and redundant if statements. For example, how should I optimize this if statement so it would be more re-usable for maintenance purposes:

   if (($game == 'DS' && $eventId == 185) || ($game == 'MT' && $eventId == 333) || ($game == 'HK' && $eventId == 51) || ($game == 'main' && $eventId == 1166) ||
            ($game == 'WT' && $eventId == 97)) {
/* some code */
}

Answer 1

I would use the most laziest option possible. Use some string concatenation and a comparison list, as you only need to compare pairs anyway:

if (in_array("$game,$eventId", array("DS,185", "MT,333", "HK,51", "main,1166", "WT,97"))) {

See in_array. You could actually use real array pairs to compare against. But in this instance there's no need.

Answer 2

Another way would be:

$eventId = $form_values['eventId'];
$game = $form_values['game'];

$games = array(
    'DS'   => 185), 
    'MT'   => 333), 
    'HK'   => 51), 
    'main' => 1166), 
    'WT'   => 97)
);

if(isset($games[$game]) && $games[$game] === $eventId) {
    /* some code */
}

It is hard to tell without knowing where else you might be using the data. If your solution structure can match the real data for the problem then you will get the best result.

I am guessing that games is more complex than just a link to an eventId. If it were more complex then it might look like this:

$games = array(
   'DS' => array('eventId'   => 185,
                 'otherData' => 'blah'),
   'MT' => array('eventId'   => 333,
                 'otherData' => 'nah')
);

if (isset($games[$game]['eventId']) && $games[$game]['eventId'] === $eventId) {
   /* some code */
}

Answer 3

This is one way you could do it:

<?php

$matches = array(
    'DS' . 185,
    'MT' . 333,
    'HK' . 51,
    'main' . 1166,
    'WT' . 97
);

print_r($matches);

$game = 'DS';
$eventId = '185';

if (in_array($game.$eventId, $matches)) {
    echo "You found a match: $game$eventId\n";
} else {
    echo "No match on: $game$eventId\n";
}

$game = 'MT';
$eventId = '185';

if (in_array($game.$eventId, $matches)) {
    echo "You found a match: $game$eventId\n";
} else {
    echo "No match on: $game$eventId\n";
}

$game = 'main';
$eventId = '1166';

if (in_array($game.$eventId, $matches)) {
    echo "You found a match: $game$eventId\n";
} else {
    echo "No match on: $game$eventId\n";
}

?>

http://codepad.org/jYGvuJxx