$arr_old = array(1,55,2,36,77);
print_r($arr_old);
/*
Array
(
    [0] => 1
    [1] => 55
    [2] => 2
    [3] => 36
    [4] => 77
)
*/
$file_name_old="test.php";
$file_old=fopen($file_name_old,"w");
fwrite($file_old,serialize($arr_old));
fclose($file_old);

$file_name_new="test.php";
$file_new=fopen($file_name_new,"r");
$file_read = fread($file_new, filesize($file_name_new)); 
fclose($file_new);
$arr_new = unserialize($file_read);
print_r($arr_new);
/*
Array
(
    [0] => 1
    [1] => 55
    [2] => 2
    [3] => 36
    [4] => 77
)
*/

------解决方案--------------------

3楼说的方法
PHP code
<?php
$yourArray = array('aqw568', 'sdtrnz2006', 'gggudf');// 原来的数组
file_put_contents('aa.txt', serialize($yourArray));// 序列化并写入文件

$readArray = unserialize(file_get_contents('aa.txt'));// 读取并反序列化

print_r($readArray);
?>