PHP Closure example

PHP Closure Example

<?php
header('Content-Type: text/plain;charset=UTF-8'); //utf-8 character with content type has html (e.g Vietnamess)

/**
 * Closure example
 *
 **/

/* #1: a sample closure without param */
$helloworld = function() {echo "hello world !"; };
$helloworld();

echo "\n----------------------------------------------\n";

/* #2: closure with param */
$hello = function($message) { echo $message; };
$hello("xin chào thế giới !");

echo "\n----------------------------------------------\n";

/* #3: closure use external variable */
$name = "Nguyễn Văn Tèo";
$print_myname = function() use ($name) { 	
	$name = $name . " hello there !";
	echo $name; 
};
$print_myname();
echo "\n";
echo $name; //variable not change after used by closure

echo "\n----------------------------------------------\n";

/* #4: Closure also can change external variable */
$total = 0;
$subTotal = function() use (&$total) {
	return $total = 30000*365;
};
echo $subTotal();
echo "\n";
echo $total;

echo "\n----------------------------------------------\n";

/* #5: Closure inside an object */
/**
* Student class
*/
class Student {	
	private $_studentName;
	private $_studentNumber;

	function __construct($name, $number) {
		$this->_studentName   = $name;
		$this->_studentNumber = $number;
	}

	public function show_info($greeting_message) {		
		$result =  function() use ($greeting_message) {			
			return "$greeting_message ! \n Student Number: {$this->_studentNumber} \n Student Name: {$this->_studentName}";
		};
		return $result();
	}
}
$nvteo = new Student("Nguyễn Văn Tèo", "1081433");
echo $nvteo->show_info("Xin chào sinh viên");

echo "\n----------------------------------------------\n";


?>