Understanding classes and objects php
In PHP web development scripts, object-oriented programming (OOP) concepts allow you to create multiple objects for a webpage and class objects allow web developers to organize these class object codes by creating source code into classes and objects. Object-oriented programming overview in PHP web development scripts helps web developers to create script code into more reusable program source code, maintainable source code, and scalable program code.
So let’s understand the concepts of class and object in PHP web development scripts.
What is a class in PHP web development scripts?
A class object in PHP web development scripts is a readymade blueprint or template format for creating a class object. It defines class properties (variables) and class methods (functions) in an existing web development script that will be in a class object created from a class. In web development programming a class does not contain realtime data, rather it helps you to create and define the structure for your favorite class data type variable object inside the class.
Syntax to define class in PHP web development script.
<?php
class testClass {
// create class Properties
public $value1;
public $value2;
// here we create Constructor used for initialize object property)
public function __construct($value1, $value2) {
$this->value1 = $value1;
$this->value2 = $value2;
}
// class Methods
public function preview() {
echo “\n Here is the value 1 – ” . $this->value1 . “<br>”;
echo “\n Here is the value 2 – ” . $this->value2 . “<br>”;
}
}
?>
Key Concepts in PHP Script Class.
- Class Properties – In PHP web development script, there are program variables defined inside the declared class, which display the condition of the existing class object.
- Class Method – In PHP web development script, there are functions defined inside the class. Which indicate the behavior of the object in the existing class.
- Class Constructor – A special method is created in PHP web script, which is called automatically when an object is created in the class. In PHP web development script, class constructor is often used to initialize the properties of the class object.
- $this – It refers to the active class object instance in PHP web development scripts.
What is Object in PHP web development scripts?
Object in PHP web development scripts is an instance of a data type variable created in a class. It contains realtime class data, and class templates are used to store this data and manipulate class data. When you create an object in a class, it is created based on the class object blueprint defined in the class.
Syntax for creating an object in PHP web development scripts.
<?php
// let Create a object from the class
$obj1 = new testClass(“Value1”, “Value2”);
// let Access the object’s properties
echo $obj1->property1; // result is – Value1
// here it Calling a method of the object
$obj1->info(); // result is – Property 1- Value1 Property 2 – Value2
?>
Key concepts in Object in PHP scripts.
- Instantiation – It is the method of creating an instance of a class in PHP web development scripts. Here objects are created in the class using the new keyword.
- Accessing Properties and Methods – Once the class object is created in PHP web development scripts, you can access the class object properties and methods using the -> operator.
Class and Object Example in PHP.
<?php
class employee {
// employee class Properties define
public $name;
public $age;
public $contact;
// employee class Constructor create
public function __construct($name, $age, $contact) {
$this->name = $name;
$this->age = $age;
$this->contact = $contact;
}
// class Method define
public function previewInfo() {
echo “\n employee detail – ” . $this->name . ” ” . $this->age . ” ” . $this->contact . “<br>”;
}
}
// hare we Creating employee objects (instances of the employee class)
$emp1 = new employee(“David”, “44”, 9414000000);
$emp2 = new employee(“Robert”, “43”, 9413000000);
// let Accessing properties and calling employee class methods
$emp1->previewInfo(); // result is – David 44 9414000000
$emp2->previewInfo(); // result is – Robert 43 9413000000
?>
Class and Object Explanation in PHP.
- Class Attributes – $name, $age, $contact indicate attributes of the Employee class.
- Class Constructor – The __construct() method initializes an object in the Employee class with the name, age, and contact specified when the class object is created.
- Class Method – The previewInfo() class method is used to display information about the Employee class.
Summary of key concepts in PHP web development scripts.
- PHP Class – A class in a PHP web script is a blueprint or user-defined data type template that defines properties and class methods for an existing class object.
- Class Object – An object is an instance of a class in PHP, which holds real-time class data type variable object data, and applies class methods to the class object.
- Class Properties and Methods – A class in a PHP web script contains class variables and functions defined inside the class.
- Class Access Modifiers – Defines class visibility of class properties and class methods (public, private, protected) in PHP webpage script.
- Class Inheritance – The PHP webpage script follows the inheritance of properties and class object methods from one class to another.
- Class static properties and methods – These are related to the class itself in PHP webpage script, and can be accessed without creating a class object.
- Class constructor and destructor – PHP webpage script has special class methods for object initialization and cleanup.
