Safe Extraction Operator in OOP in PHP

The safe extraction operator ?-> allows safely accessing methods and properties of objects that can be null.

Let's look at an example. Suppose we have the following class:

php<?php
  class User
  {
    public $name;
    
    public function __construct($name)
    {
      $this->name = $name;
    }
  }
?>

Let's create an object of this class:

php<?php
  $user = new User('john');
?>

Let's output the value of its property:

php<?php
  $user = new User('john');
  echo $user->name;
?>

Suppose now it happened that instead of an object we have null. In this case, an attempt to access the user's name will lead to an error:

php<?php
  $user = null;
  echo $user->name; // error
?>

To suppress the error, we can use the safe extraction operator:

php<?php
  $user = null;
  echo $user?->name;
?>

php<?php
  class Employee {
    public $name;
    public $salary;
    
    public function __construct($name, $salary)
    {
      $this->name = $name;
      $this->salary = $salary;
    }
  }
  
  $employee = new Employee('john', 1000);
  
  echo $employee->name;
  echo $employee->salary;
?>