介紹幾個 php4 中非常有用的數組函數

1 void extract (array var_array [, int extract_type ][, string prefix]])
把一個關聯數組展開為變量名和變量的值，如果有沖突則由后面的參數指定處理方法！
如：

<php?

/* Suppose that $var_array is an array returned from
wddx_deserialize */

$size = "large";
$var_array = array ("color" => "blue",
"size" => "medium",
"shape" => "sphere");
extract ($var_array, EXTR_PREFIX_SAME, "wddx");

print "$color, $size, $shape, $wddx_sizen";

?>

2 array compact (mixed varname [, mixed ...])
和上面的函數相反，把變量名和變量的值保存到關聯數組里面！
如：
$city = "San Francisco";
$state = "CA";
$event = "SIGGRAPH";

$location_vars = array ("city", "state");

$result = compact ("event", "nothing_here", $location_vars);

$result 結果為 array ("event" => "SIGGRAPH", "city" => "San Francisco", "state" => "CA").


3 bool in_array (mixed needle, array haystack)
判斷數組中是否有這個值

4 void natsort (array array)
以自然數的方法排序數組，這時 12 將排在2的后面
$array1 = $array2 = array ("img12.png","img10.png","img2.png","img1.png");

sort($array1);
echo "標準排序n";
print_r($array1);

natsort($array2);
echo "n自然排序n";
print_r($array2);

代碼輸出為:

標準排序
Array
(
[0] => img1.png
[1] => img10.png
[2] => img12.png
[3] => img2.png
)

自然排序
Array
(
[3] => img1.png
[2] => img2.png
[1] => img10.png
[0] => img12.png
) 

原文轉自：http://www.anti-gravitydesign.com