constant php code example
Example 1: php const
<?php
define('CONSTANT', 'Hello world !');
const CONSTANT = 'Hello world !';
const NEW_CONSTANT = CONSTANT.' And beyond...';
const ANIMALS = array('dog', 'cat', 'ant');
define('ANIMALS', array('dog', 'cat', 'ant'));
?>
Example 2: how to store connection object in the constant in php
<?php
include_once('IConnectInfo.php');
class Database implements IConnectInfo
{
private static $instance = null;
private $conn;
private $server = IConnectInfo::HOST;
private $currentDB = IConnectInfo::DBNAME;
private $user = IConnectInfo::UNAME;
private $pass = IConnectInfo::PW;
private function __construct()
{
try {
$this->conn = new PDO("mysql:host=$this->server;dbname=$this->currentDB", $this->user, $this->pass
);
$this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->conn->exec('set names utf8');
echo $this->server . " connected successfully" . PHP_EOL;
} catch (PDOException $e) {
echo "Connection failed: " . $e->getMessage();
die;
}
}
public static function getInstance()
{
if (!self::$instance) {
self::$instance = new Database();
}
return self::$instance;
}
public function getConnection()
{
return $this->conn;
}
public function getSelectQueryResult($query = '')
{
try {
$query = $this->conn->prepare($query);
$query->execute();
return $query->fetchAll(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
echo $query . "<br>" . $e->getMessage();
}
}
}