以下为引用的内容：

// this is relative to the loaded script's path
// it may cause problems when running scripts from different directories
require_once('config/database.php');

// this is always relative to this file's path
// no matter where it was included from
require_once(dirname(__FILE__) . '/config/database.php');

以下为引用的内容：

// some code
// ...
my_debug("some debug message", __LINE__);
/* prints
Line 4: some debug message
*/

// some more code
// ...
my_debug("another debug message", __LINE__);
/* prints
Line 11: another debug message
*/

function my_debug($msg, $line) {
 echo "Line $line: $msg

以下为引用的内容：

// generate unique string
echo md5(time() . mt_rand(1,1000000));
There is actually a PHP function named uniqid() that is meant to be used for this.

// generate unique string
echo uniqid();
/* prints
4bd67c947233e
*/

// generate another unique string
echo uniqid();
/* prints
4bd67c9472340
*/

以下为引用的内容：

// with prefix
echo uniqid('foo_');
/* prints
foo_4bd67d6cd8b8f
*/

// with more entropy
echo uniqid('',true);
/* prints
4bd67d6cd8b926.12135106
*/

// both
echo uniqid('bar_',true);
/* prints
bar_4bd67da367b650.43684647
*/

以下为引用的内容：

// a complex array
$myvar = array(
 'hello',
 42,
 array(1,'two'),
 'apple'
);

// convert to a string
$string = serialize($myvar);

echo $string;
/* prints
a:4:{i:0;s:5:"hello";i:1;i:42;i:2;a:2:{i:0;i:1;i:1;s:3:"two";}i:3;s:5:"apple";}
*/

// you can reproduce the original variable
$newvar = unserialize($string);

print_r($newvar);
/* prints
Array
(
    [0] => hello
    [1] => 42
    [2] => Array
        (
            [0] => 1
            [1] => two
        )

    [3] => apple
)
*/

以下为引用的内容：

// a complex array
$myvar = array(
 'hello',
 42,
 array(1,'two'),
 'apple'
);

// convert to a string
$string = json_encode($myvar);

echo $string;
/* prints
["hello",42,[1,"two"],"apple"]
*/

// you can reproduce the original variable
$newvar = json_decode($string);

print_r($newvar);
/* prints
Array
(
    [0] => hello
    [1] => 42
    [2] => Array
        (
            [0] => 1
            [1] => two
        )

    [3] => apple
)
*/