PHP sort 2d string array by specific order array [duplicate]

Question

I'm new to php and have been trying to sort a 2d array of strings, with a specific order array. Have been looking at using 'usort' and 'comparison', but cant seem to wrap my head around them when using 2d array and strings.

Need to input array to method and return sorted array, with same format. So for each entry in array it will sort the 2nd level 'file' value dependant on the order of order array. Any suggestions how to accomplish this?

//actual array to be sorted by 'file'
$Array ( 
[0] => Array ( [source] => img/table/icon/toxic.svg [file] => toxic ) 
[1] => Array ( [source] => img/table/icon/health.svg [file] => health ) 
[2] => Array ( [source] => img/table/icon/irritant.svg [file] => irritant   ));

//order array with desired sort order
$order = array("irritant","corrosive","environment" ,"health","toxic","oxidizing","flammable","explosive","gas");

//Desired Output Result
$Array ( 
[0] => Array ( [source] => img/table/icon/irritant.svg [file] => irritant )
[1] => Array ( [source] => img/table/icon/health.svg [file] => health ) 
[2] => Array ( [source] => img/table/icon/toxic.svg [file] => toxic ) );

See so irritant is first and toxic is last :)

xathien · Accepted Answer · 2015-04-07 15:25:22Z

1

This can be accomplished through clever use of PHP's usort function. Your call may look something like this:

$order = array("irritant","corrosive","environment" ,"health","toxic","oxidizing","flammable","explosive","gas");
usort($array, function ($a, $b) use ($order) {
    $aOrder = array_search($a['file'], $order);
    $bOrder = array_search($b['file'], $order);
    if ($aOrder == $bOrder) return 0;
    return ($aOrder > $bOrder) ? 1 : -1;
});

answered Apr 7, 2015 at 15:25

xathien

8127 silver badges10 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Orbitall Over a year ago

This that much more effcient to use? just tried it and get an empty array when printing result...probs jus me n my understanding tho.

xathien Over a year ago

It would be measurably more efficient on large arrays than doing it in raw PHP, as usort() does it both in-place and using C, making it more memory- and time-efficient.

zgr024 · Accepted Answer · 2015-04-07 15:30:58Z

0

The basic method is to iterate through both the array and the order array and reassign the keys into a new array...

<?php
    $a[] = array('source' => 'img/table/icon/toxic.svg','file'=>'toxic');
    $a[] = array('source' => 'img/table/icon/health.svg','file'=>'health');
    $a[] = array('source' => 'img/table/icon/irritant.svg','file'=>'irritant');

    $b = array();

    $order = array("irritant","corrosive","environment","health","toxic","oxidizing","flammable","explosive","gas");

    foreach ($a as $arr) {
        foreach ($order as $key => $o) {
            if ($o == $arr['file']) {
                $b[$key] = $arr;
                break;
            }
        }
    }
    ksort($b);
    print_r(array_values($b)); // or print_r($b); if you dont want sequential keys
?>

output:

Array ( 
[0] => Array ( [source] => img/table/icon/irritant.svg [file] => irritant ) 
[1] => Array ( [source] => img/table/icon/health.svg [file] => health ) 
[2] => Array ( [source] => img/table/icon/toxic.svg [file] => toxic )
)

edited Apr 7, 2015 at 15:30

answered Apr 7, 2015 at 15:24

zgr024

1,1931 gold badge12 silver badges27 bronze badges

2 Comments

Orbitall Over a year ago

Thanks that works a treat....looks simple, but wudve taken me a while to figure out using arrayflip and ksort.

zgr024 Over a year ago

you dont even need the array_flip... see my last edit. It can be done without that. Also glad I could help. The usort method that xathien suggested will also work, but for a novice to PHP, it doesn't explain anything.

Collectives™ on Stack Overflow

PHP sort 2d string array by specific order array [duplicate]

2 Answers 2

2 Comments

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Linked

Related