Accessing Property by Variable Name in OOP in PHP

You can access object properties by a variable name. Let's see how this can be done. Suppose we have the following class User:

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

Let's create an object of this class:

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

Let's output the value of its property:

php<?php
  echo $user->name; // outputs 'john'
?>

Suppose we have a variable that stores the property name:

php<?php
  $prop = 'name';
?>

Now let's use the variable value as the property name:

php<?php
  $prop = 'name';
  echo $user->$prop; // outputs 'john'
?>

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

php<?php
  $prop1 = 'name';
  $prop2 = 'salary';
?>