Example
Constants can be defined inside classes using a const keyword.
class Foo {
const BAR_TYPE = "bar";
// reference from inside the class using self::
public function myMethod() {
return self::BAR_TYPE;
}
}
// reference from outside the class using <ClassName>::
echo Foo::BAR_TYPE;
This is useful to store types of items.
<?php
class Logger {
const LEVEL_INFO = 1;
const LEVEL_WARNING = 2;
const LEVEL_ERROR = 3;
// we can even assign the constant as a default value
public function log($message, $level = self::LEVEL_INFO) {
echo "Message level " . $level . ": " . $message;
}
}
$logger = new Logger();
$logger->log("Info"); // Using default value
$logger->log("Warning", $logger::LEVEL_WARNING); // Using var
$logger->log("Error", Logger::LEVEL_ERROR); // using class
