$this in PHP

In PHP, $this is a special variable used inside a class to refer to the current instance of the class. It is used to access the properties and methods of the current object.

Key Uses of $this link

1. Accessing Properties

   You can use $this to access the properties of the current object.

     <?php
   class Car {
       public $make;
       public $model;
   
       public function __construct($make, $model) {
           $this->make = $make;
           $this->model = $model;
       }
   
       public function displayInfo() {
           echo "Make: " . $this->make . ", Model: " . $this->model;
       }
   }
   
   $car = new Car("Toyota", "Corolla");
   $car->displayInfo(); // Outputs: Make: Toyota, Model: Corolla
   ?>
     

2. Calling Methods

   You can use $this to call other methods within the same class.

     <?php
   class Calculator {
       public function add($a, $b) {
           return $this->calculateSum($a, $b);
       }
   
       private function calculateSum($a, $b) {
           return $a + $b;
       }
   }
   
   $calc = new Calculator();
   echo $calc->add(5, 10); // Outputs: 15
   ?>
     

3. Chaining Methods

   You can use $this to return the current instance from a method, allowing for method chaining.

     <?php
   class Person {
       private $name;
   
       public function setName($name) {
           $this->name = $name;
           return $this; // Return current instance
       }
   
       public function getName() {
           return $this->name;
       }
   }
   
   $person = new Person();
   echo $person->setName("Alice")->getName(); // Outputs: Alice
   ?>
     

4. Accessing the Current Instance

In object-oriented programming, $this is essential for interacting with the current object instance, especially within methods, constructors, and when accessing or modifying instance properties and methods.

Key Points link

• Instance Reference: $this refers to the current instance of the class.
• Property and Method Access: Use $this to access or modify properties and call methods within the same object.
• Method Chaining: Return $this from methods to enable chaining of method calls.