What is the difference between setter methods and construct methods? - php

Question

If I have a setter and getter methods below :
<?php
class Name{
protected $first ;
public function setNameType($value) {
$this->first = $value;
}
public function getNameType() {
return $this->first;
}
}
$name = new Name;
$name->setNameType("My Name");
echo $name->getNameType();
?>
and a construct method like this
<?php
class Name{
protected $first ;
public function __construct($value) {
$this->first = $value;
}
public function getNameType() {
return $this->first;
}
}
$name = new Name("My Name");
echo $name->getNameType();
?>
Can I use the two interchangeably at all times or is there situations where one will be most prefered over the other ?

Answer 1

There is also some great explaination about your question: http://www.potstuck.com/2009/01/08/php-dependency-injection/

Answer 2

Try this website. It explains all with examples.
http://ralphschindler.com/2012/03/09/php-constructor-best-practices-and-the-prototype-pattern

Answer 3

Generally you would use constructors to set values if your class cannot exist or doesn't make sense without the value. If the value is allowed to be changed, than add a setter. If it should never be changed after construction, then don't add a setter.

Answer 4

An example code:
class Book {
public function __construct() {
$registry = RegistrySingleton::getInstance();
$this->_database = $registry->database;
// or
global $databaseConnection;
$this->_database = $database;
}
}
class Book {
private $_databaseConnection;
public function __construct() { }
public function setDatabaseConnection($databaseConnection) {
$this->_databaseConnection = $databaseConnection;
}
}
$book = new Book();
$book->setDatabase($databaseConnection);
$book = new Book($databaseConnection, $configFile);
$book = new Book();
$book->setDatabase($databaseConnection);
$book->setConfigFile($configFile);
class Container {
public static $_database;
public static function makeBook() {
$book = new Book();
$book->setDatabase(self::$_database);
// more injection...
return $book;
}
}
And then:
$book = Container::makeBook();