Question

I have an array, that I construct within a mysql fetch array loop. This array contains values such as:

Array ( [0] => 1 Hour: 1.6
        [1] => 2 Hour: 2.3
        [2] => 3 Hour: 2.8
        [3] => 4 Hour: 3.7
        [4] => 8 Hour: 7.0 )

Array ( [0] => 2 Hour: 1.5
        [1] => 4 Hour: 2.9
        [2] => 8 Hour: 3.8
        [3] => 12 Hour: 5.0
        [4] => 24 Hour: 8.9 )

What is the best way to sort the cheapest prices for a given duration, so if I select one hour, I still get the second two hours returned as the cheapest.

To further complicate this the array may sometimes contain:

Array ( [0] => Free )

I was thinking creating a class with a getPrice(duration) function, within my loop I would declare a new instance of this and add a pointer to a global array, before finally looping through each item in this global array to find the cheapest. Is this solution viable? or is there a better alternative?

while($row = mysql_fetch_array($results))
{
    $price = explode(';', $row['price']);
    print_r($price);
}

Thanks

Answer 1

You should sort in the database before these values even get back to PHP, no need to do the extra work on the Webserver.

For the ‘FREE’ values, just use MySQL to turn them to 0 so that the ORDER BY operation works correctly.

EDIT:

Though I feel there is probly a better solution talking through and tweaking the DB paradigm here I’ve decided to acquiesce and provide OP w/ the type of answer he’s after (w/ the minimal info provided, I still think this is probly close):

$aData = array(
        array(
            '1 Hour: 1.6',
            '2 Hour: 2.3',
            '3 Hour: 2.8',
            '4 Hour: 3.7',
            '8 Hour: 7.0'),
        array(
            '2 Hour: 1.5',
            '4 Hour: 2.9',
            '8 Hour: 3.8',
            '12 Hour: 5.0',
            '24 Hour: 8.9'),
        array(
            '2 Hour: Free',
            '4 Hour: 5.9',
            '8 Hour: 3.5',
            '12 Hour: 6.0',
            '24 Hour: 7.9'),
        );


$aCheapest = array();

// iterate all rows
foreach($aData as $aInfo) {
    // iterate row items
    foreach($aInfo as $aRow) {
        // parse the duration and rate
        list($sRawDuration, $fRate) = explode(': ', $aRow);

        $iDuration = (int)str_replace(' Hour', '', $sRawDuration);
        if(strtolower($fRate) == 'free')
            $fRate = 0.0;
        else
            $fRate = (float)trim($fRate);

        // potentially update the cheapest rate for a duration
        if(!isset($aCheapest[$iDuration]))
            $aCheapest[$iDuration] = $fRate;
        else
            $aCheapest[$iDuration] = min($aCheapest[$iDuration], $fRate);
    }
}

var_dump($aCheapest);

Output:

array(7) {
  [1]=>
  float(1.6)
  [2]=>
  float(0)
  [3]=>
  float(2.8)
  [4]=>
  float(2.9)
  [8]=>
  float(3.5)
  [12]=>
  float(5)
  [24]=>
  float(7.9)
}