PHP: htmlentities() function

PHP: Tips of the Day

Constants can be defined inside classes using a const keyword.

Example:

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;

Output:

bar

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

Output: