In this tutorial, you shall learn how to about constructors in a class in PHP, and how to define a class constructor, with the help of example programs.
PHP – Class Constructor
A constructor in a class is used to initialise the properties of the class objects.
To define a constructor for a class in PHP, define __constructor() method in the class, just like any other function in a class, as shown in the following syntax.
class ClassName() {
function __construct(parameters) {
//constructor body
}
}
function
is keyword__construct
is the function name, and is fixed for a constructor in classparameters
: comma separated parameters that this constructor can accept as arguments.
Example
In our previous tutorials in PHP classes and objects series, we have given an example class Person
. We shall continue with this class Person
to demonstrate how to define a constructor for a class.
Now, let us define a constructor for the class Person
. And create an object with arguments passed for the constructor.
PHP Program
<?php
class Person {
protected string $fullname;
protected int $age;
public function __construct(string $fullname = null, int $age = null) {
$this->fullname = $fullname;
$this->age = $age;
}
public function printDetails() {
echo "Name : " . $this->fullname . "<br>Age : " . $this->age;
}
}
//create object of type Person with arguments passed for constructor
$person1 = new Person("Mike Turner", 24);
//call method on the object
$person1->printDetails();
?>
Output
Conclusion
In this PHP Tutorial, we learned how to define a constructor for a class, with examples.