Destructor method in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a destructor method in PHP?

A destructor method is a special function in a PHP class that runs automatically when an object is destroyed or goes out of scope. It is used to clean up resources like closing files or database connections.

beginner

How do you name a destructor method in PHP?

In PHP, the destructor method is named __destruct() with two underscores at the start. It does not take any parameters.

beginner

When is the destructor method called in PHP?

The destructor method is called automatically when the object is no longer needed, such as when the script ends, the object is unset, or it goes out of scope.

beginner

What is a common use case for a destructor method?

A common use case is to release resources like closing database connections, freeing memory, or saving data before the object is destroyed.

beginner

Write a simple PHP class with a destructor that prints a message when the object is destroyed.

Example:<br><pre>&lt;?php
class MyClass {
  public function __destruct() {
    echo "Object destroyed!";
  }
}
$obj = new MyClass();
// When script ends or object is unset, it prints: Object destroyed!
?&gt;</pre>

What is the correct name of the destructor method in PHP?

A __destruct()

B destruct()

C __destroy()

D delete()

The destructor method in PHP is always named __destruct() with two underscores.

When is the destructor method called automatically?

A When a method is called

B When the object is created

C When the object is destroyed or goes out of scope

D When a variable is assigned

The destructor runs automatically when the object is destroyed or no longer needed.

Which of these is a common use for a destructor?

A Creating a new object

B Reading user input

C Starting a session

D Closing a database connection

Destructors are often used to clean up resources like closing database connections.

Can the destructor method take parameters in PHP?

A No, it cannot take parameters

B Yes, it can take any number of parameters

C Yes, but only one parameter

D Only optional parameters

The destructor method __destruct() does not accept any parameters.

What happens if you unset an object in PHP?

A The object is copied

B The destructor method is called

C Nothing happens

D The constructor method is called

Unsetting an object triggers the destructor method to run.

Explain what a destructor method is and when it is used in PHP.

Think about what happens when an object is no longer needed.

Write a simple PHP class with a destructor that outputs a message when the object is destroyed.

Use __destruct() and echo inside it.