I've two PHP Arrays. The first one contains a sort order. The second one contains the data which i need to sort. I have no idea how to solve it…
What I'm trying to get is a list, sorted by the values of the first array (order.txt). Any suggestions?
<li>Item [2]</li>
<li>Item [1]</li>
<li>Item [3]</li>
Array
(
[0] => 2
[1] => 1
[2] => 3
)
Array
(
[0] => Array
(
[id] => 1
[name] => 00134258.jpg
[size] => 2787
)
[1] => Array
(
[id] => 2
[name] => 80132454.jpg
[size] => 2667
)
[2] => Array
(
[id] => 3
[name] => 13134218.jpg
[size] => 2787
)
)
Here are the code which produces the arrays above:
<?php
$order = file('order.txt');
foreach ($order as $key => $value) {
$order = json_decode($value, true);
}
print_r($order);
$file = file('db.txt');
foreach ($file as $key => $value) {
$file_data[] = json_decode($value, true);
}
print_r($file_data);
?>
This are the json strings:
{"0":"2","1":"1","2":"3"}
{"id":"1","name":"00134258.jpg","size":2787}
{"id":"2","name":"80132454.jpg","size":2667}
{"id":"3","name":"13134218.jpg","size":2787}
Make a new array where the keys are the id of the data, then loop through your order array and assign the values to an ordered array...
<?php
// loop through the file data
foreach($file_data as $v){
// assign values to new array with the data id as it's key
$identified[$v['id']] = $v;
}
// loop through the order array
foreach($order as $v){
// pull the data values from the identified array by their key
$ordered[] = $identified[$v];
}
// check it has all worked out as planned ;)
print_r($ordered);
?>
Alternatively... in line with @hakre's method, first create array ordered by index, and then use array_multisort method.
<?php
foreach($file_data as $v){
$ordered[$v['id']] = $v;
}
array_multisort($order, $ordered);
print_r($ordered);
?>
From your $order
array substract 1 from each value, then use array_multisort
:
foreach($order as &$o) $o--;
unset($o);
array_multisort($order, $data);
This works as long as the id
value is always one higher than it's offset in $data
.