php比较多维数组中值的大小排序实现代码

代码如下:

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.jb51.net/image.gif' ,
o_detail => 人人,
vote_num => 1
),

1 => Array
(
o_id => 1844,
o_name => 芭比,
o_pic => 'http://upload.jb51.net/game_image/dfxxz/dfVIP.files/shenxiandao.jpg',
o_detail => 也是美女呢,
vote_num => 2
),

2 => Array
(
o_id => 1843,
o_name => 程程,
o_pic => 'http://g.jb51.net./upload_img/2011-06/31554_4d0088da7a61ad9c8c02a530be94d98e.png',
o_detail => 美女哦,
vote_num => 3
)
);
uasort($arr, ”cmp“);
echo ‘

'; 
print_r ($arr); 
echo ‘'; 
 
返回 
  代码如下:
 
Array 
( 
[2] => Array 
( 
[o_id] => 1843 
[o_name] => 程程 
[o_pic] => http://g.jb51.net./upload_img/2011-06/31554_4d0088da7a61ad9c8c02a530be94d98e.png 
[o_detail] => 美女哦 
[vote_num] => 3 
) 
[1] => Array 
( 
[o_id] => 1844 
[o_name] => 芭比 
[o_pic] => http://upload.jb51.net/game_image/dfxxz/dfVIP.files/shenxiandao.jpg 
[o_detail] => 也是美女呢 
[vote_num] => 2 
) 
[0] => Array 
( 
[o_id] => 1861 
[o_name] => 2 
[o_pic] => http://g.jb51.net/image.gif 
[o_detail] => 人人 
[vote_num] => 1 
) 
)