PHP usort: sort an array of records using a particular sequence
With PHP's usort function you are sorting an array using a custom function you have made:
function sort_by_title($a,$b)
{
return strcasecmp($a['title'], $b['title']);
}
$myArray[0]['id'] = 1;
$myArray[0]['title'] = 'Hello';
$myArray[1]['id'] = 5;
$myArray[1]['title'] = 'Foo';
$myArray[2]['id'] = 6;
$myArray[2]['title'] = 'Foo etc';
.... and so on
usort($myArray, 'sort_by_title');
How about sorting the same array using a particular sequence of either ids, titles or whatever field of the record (using an array)?
Here is the solution:
(this example sorts the above array by a sequence that refers to the title field)
function sort_by_seq($a,$b)
{
$seq = array('Foo', 'Hello', 'Foo etc');
return array_search($a['title'], $seq) - array_search($b['title'], $seq);
}
usort($myArray, 'sort_by_seq');
Check out also another (sql related) tip for sorting sql result rows:
http://programming.pblogs.gr/general-tips.html which will be updated continuity with new tips.
