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PHP Object-Oriented PHP Basics (Retired) Properties and Methods Methods

I couldnt get what "->" actually mean. could you please explain?

in the course "methods" in PHP there is expresion "->" e.g.: $p->getinfo() $this->....

i couldn't completely understand what "->" does.

3 Answers

At it's most basic, it's a way of accessing stuff inside a class. A class can have methods and properties and these can be pulled out by using the ->operator.

Let's say we're talking about you. We could have Your->name, Your->age, Your->phoneNumber.

You would access the information about yourself like this:

<?php

$jumper = new Person;

$jumper->firstName; // 'Jumper'

$jumper->lastName; // 'Lejava'

$jumper->age; // 1040

$jumper->phoneNumber; // 01234123456

and the class of Person would need to look like this.

<?php

class Person {

  /**
   * @var $firstName string
   */
  public $firstName = 'Jumper';

  /**
   * @var $lastName string
   */
  public $lastName = 'Lejava';

  /**
   * @var $age integer
   */
  public $age = 1040;

  /**
   * @var $phoneNumber integer
   */
  public $phoneNumber = 01234123456;

}

Right now, you can think of methods being exactly the same as functions, but you can make them a little cooler. Let's say you wanted to do this:

<?php

$fullName = fullName($jumper->firstName, $jumper->lastName); // 'Jumper Lejava'

and your function would look like this.

<?php

function fullName($firstName, $lastName) {
  return $fullName .' '. $lastName;
}

This is something you can do in your object. Add a method like so - again using the ->operator to call a method that belongs to your object.

<?php

$jumper->fullName(); // 'Jumper Lejava'

You class would need to be updated to look like this:

<?php

class Person {

  /**
   * @var $firstName string
   */
  public $firstName = 'Jumper';

  /**
   * @var $lastName string
   */
  public $lastName = 'Lejava';

  /**
   * @var $age integer
   */
  public $age = 1040;

  /**
   * @var $phoneNumber integer
   */
  public $phoneNumber = 01234123456;


  /**
   * The Persons full name
   *
   * @return $fullName string
   */
  public function fullName()
  {
    return $this->firstName .' '. $this->lastName;
  }
}

Hope this adds to your understanding!

Notice the use of $this. $this refers to THIS very instance of the object. It is a special variable and can't be used for anything else.

Tony Brackins
Tony Brackins
28,766 Points

wow. This explanation is amazing.

Hugo Paz
Hugo Paz
15,622 Points

Hi Jumper,

The -> is used to access a method or property on an object. Lets say you have the following class:

<?php

class User{
    public $name;

    public function get_name(){
        return $this->name;

    }
}

$u = new User;

$u->name = "Peter";

$user_name = $u->get_name();

echo $user_name;

?>

This will echo out "Peter".

Lets explain this step by step:

  1. You create a class called User with a property (name) and a method (get_name)
  2. You set the property name to "John".
  3. The method returns $this->name, this means that if when you create a User object, it will return the object(this) name.
  4. You create a new user object ($u = new User;).
  5. You set the object name to 'Peter'.
  6. You then create a variable which will receive the value of the object name ($user_name = $u->get_name() )
  7. You then echo the value of the variable.

This is a simple example but i hope you are able to understand it.

Great explanation. Thank you! Did you correct your example code? I don't see the second step: "You set the property name to "John".

kabir k
PLUS
kabir k
Courses Plus Student 18,036 Points

In addition to the explanation already given, it's called an object operator.