php compares the size sort implementation code for values in multidimensional arrays

If the values are not repeated, you can swap the keys and values with array_flip(), then krsort(), and finally array_flip() to compare the sizes. If you want to intercept an array, you can use array_slice().

If you have duplicate values, you'll need to use some sorting algorithms, but php has a powerful function called uasort(), which USES a custom comparison function to sort the values in an array and keep the index associated, and usort() to rebuild the index.

 
function cmp($a, $b){ 
if ($a["vote_num"] == $b["vote_num"]) { 
return 0; 
} 
return ($a["vote_num"] > $b["vote_num"]) ? -1 : 1; 
} 

$arr = Array 
( 
0 => Array 
( 
o_id => 1861, 
o_name => 2, 
o_pic => 'http://g.ofstack.com/image.gif' , 
o_detail =>  everyone , 
vote_num => 1 
), 

1 => Array 
( 
o_id => 1844, 
o_name =>  barbie , 
o_pic => 'http://upload.ofstack.com/game_image/dfxxz/dfVIP.files/shenxiandao.jpg', 
o_detail =>  She's a beauty, too. , 
vote_num => 2 
), 

2 => Array 
( 
o_id => 1843, 
o_name =>  Love never fails , 
o_pic => 'http://g.ofstack.com./upload_img/2011-06/31554_4d0088da7a61ad9c8c02a530be94d98e.png', 
o_detail =>  The beauty oh , 
vote_num => 3 
) 
); 
uasort($arr,  " cmp " ); 
echo  ' < pre style="text-align:left" >'; 
print_r ($arr); 
echo  ' < / pre >'; 

return

 
Array 
( 
[2] => Array 
( 
[o_id] => 1843 
[o_name] =>  Love never fails  
[o_pic] => http://g.ofstack.com./upload_img/2011-06/31554_4d0088da7a61ad9c8c02a530be94d98e.png 
[o_detail] =>  The beauty oh  
[vote_num] => 3 
) 
[1] => Array 
( 
[o_id] => 1844 
[o_name] =>  barbie  
[o_pic] => http://upload.ofstack.com/game_image/dfxxz/dfVIP.files/shenxiandao.jpg 
[o_detail] =>  She's a beauty, too.  
[vote_num] => 2 
) 
[0] => Array 
( 
[o_id] => 1861 
[o_name] => 2 
[o_pic] => http://g.ofstack.com/image.gif 
[o_detail] =>  everyone  
[vote_num] => 1 
) 
)