Re: singleton
| From: | Sebastian Bergmann | Date: | Fri, 21 Jun 2002 06:15:13 +0000 |
| Subject: | Re: singleton | ||
| References: | 1 | Groups: | php.dev |
| Request: | Send a blank email to php-dev+get-85428@lists.php.net to get a copy of this message | ||
Purushotham Komaravolu wrote:
> Is there any way to create a singleton in Php4?
Yes, but this is the wrong list to ask such questions.
Anyhow:
PHP 4
<?php
class Singleton {
function &getInstance() {
static $instance;
if (!isset($instance)) {
echo "Creating new object.\n";
$instance = new Singleton;
}
return $instance;
}
}
$a = Singleton::getInstance();
$b = Singleton::getInstance();
if ($a === $b) {
echo '$a and $b reference the same object.' . "\n";
}
?>
PHP 5
<?php
class Singleton {
static $instance = null;
function getInstance() {
if (self::$instance == null) {
echo "Creating new object.\n";
self::$instance = new Singleton;
}
return self::$instance;
}
}
$a = Singleton::getInstance();
$b = Singleton::getInstance();
if ($a === $b) {
echo '$a and $b reference the same object.' . "\n";
}
?>
--
Sebastian Bergmann
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