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PHP Methods

Methods are functions that belong to a class.

They define what an object can do.

Examples:

Player
│
├── sendMessage()
├── teleport()
├── kick()
└── addMoney()

Properties describe:

WHAT an object IS

Methods describe:

WHAT an object DOES

Real Life Example

Car:

Properties:

brand
speed
color
fuel

Methods:

start()
stop()
accelerate()
brake()

Declaring Methods

class Player {

    public function hello() {

        echo "Hello";

    }

}

Calling Methods

$player =
new Player();

$player->hello();

Output:

Hello

Visualization

Player Object
│
├── name
├── money
│
├── sendMessage()
├── addMoney()
└── teleport()

Multiple Methods

class Player {

    public function join() {

        echo "Joined";

    }

    public function leave() {

        echo "Left";

    }

}

Methods With Parameters

Methods can receive data.

class Player {

    public function sendMessage(
        string $message
    ) {

        echo $message;

    }

}

Usage:

$player->sendMessage(
    "Hello World"
);

Multiple Parameters

public function teleport(

    float $x,
    float $y,
    float $z

) {

}

Methods Returning Values

public function getMoney(): int {

    return 5000;

}

Usage:

echo
$player->getMoney();

Return Types

Methods should always declare return types.

Available:

int
string
float
bool
array
object
void
mixed
never

Void Methods

public function kick(): void {

}

Means:

Returns nothing.

Returning Objects

public function getServer()
: Server {

}

Returning Nullable Objects

public function getTarget()
: ?Player {

}

Means:

Player OR null

Method Visibility

Methods support:

public
protected
private

Public Methods

Accessible everywhere.

public function hello() {

}

Protected Methods

Only current class and child classes.

protected function save() {

}

Private Methods

Only current class.

private function encrypt() {

}

Example

class Bank {

    private function verify() {

    }

}

Nobody outside can call:

$bank->verify();

The $this Keyword

Inside methods:

$this

refers to current object.

Example:

class Player {

    public int $money = 0;

    public function addMoney(
        int $amount
    ): void {

        $this->money +=
            $amount;

    }

}

Example

$player =
new Player();

$player->addMoney(
    1000
);

echo
$player->money;

Output:

1000

Why $this Exists

Imagine:

$p1
$p2
$p3

Each object has its own money.

$this

automatically refers to correct object.

Method Chaining

Methods can return:

$this

Example:

public function setName(
    string $name
): self {

    $this->name =
        $name;

    return $this;

}

Usage:

$player
    ->setName("Aayan")
    ->setRank("Owner")
    ->setMoney(5000);

Self Return Type

public function test()
: self {

    return $this;

}

Means:

Returns current class.

Fluent Interface

Popular in Laravel.

Example:

$query
    ->where()
    ->orderBy()
    ->limit();

Method Overloading

PHP does not support true method overloading.

Invalid:

public function test() {}

public function test(
    string $name
) {}

Error.

Alternative

Use:

mixed

or

...$args

Example:

public function test(
    mixed ...$args
) {

}

Named Arguments

PHP 8+

createPlayer(

    name: "Aayan",
    money: 5000

);

Recursive Methods

Methods may call themselves.

Example:

public function factorial(
    int $n
): int {

    if ($n <= 1) {
        return 1;
    }

    return
        $n *
        $this->factorial(
            $n - 1
        );

}

Static Methods

Belong to class itself.

public static function create() {

}

Usage:

Player::create();

Example

class Math {

    public static function add(
        int $a,
        int $b
    ): int {

        return $a + $b;

    }

}

Usage:

Math::add(
    5,
    10
);

Abstract Methods

Can be declared without implementation.

abstract public function save();

Covered later.

Final Methods

Prevent overriding.

final public function getId() {

}

Covered later.

Real PocketMine Examples

Sending Message

$player->sendMessage(
    "Hello"
);

Teleporting

$player->teleport(
    $position
);

Getting Name

$player->getName();

Server Broadcast

$this->getServer()
    ->broadcastMessage(
        "Restarting"
    );

Event Example

public function onJoin(
    PlayerJoinEvent $event
): void {

    $player =
        $event->getPlayer();

    $player->sendMessage(
        "Welcome!"
    );

}

Method Call Stack

Example:

A()
 ↓
B()
 ↓
C()

Each method creates a stack frame.

Memory Representation

Object
│
├── Properties
└── Methods

Methods are stored once.

Properties are unique per object.

Common Beginner Mistakes

Forgetting Parentheses​

Wrong:

$player->sendMessage;

Correct:

$player->sendMessage();

Forgetting Return​

Wrong:

public function getMoney()
: int {

}

Must return integer.

Accessing Undefined Methods​

Wrong:

$player->abc();

Using Static Incorrectly​

Wrong:

$this->create();

if method is static.

Correct:

self::create();

Best Practices

✅ Use return types.

✅ Keep methods small.

✅ One responsibility per method.

✅ Avoid huge methods.

✅ Prefer meaningful names.

Naming Examples

Good:

sendMessage()
getMoney()
setRank()
teleport()

Bad:

abc()
test()
method1()

Exercises

Exercise 1​

Create:

class Car {

    public function start() {

    }

}

Exercise 2​

Create:

Player

Methods:

sendMessage()
kick()
ban()

Exercise 3​

Create:

Economy

Methods:

addMoney()
removeMoney()
hasMoney()

Mini Project

Create:

class Player {

    private string $name;

    private int $money;

    public function addMoney() {}

    public function removeMoney() {}

    public function sendMessage() {}

}

Quiz

What are methods?​

Answer

Functions belonging to classes.

Which keyword refers to current object?​

Answer
$this

Which operator calls methods?​

Answer
->

Which keyword creates class methods?​

Answer
function

Which keyword creates static methods?​

Answer
static

Real PocketMine Architecture

Player
│
├── sendMessage()
├── teleport()
├── kick()
├── setGamemode()
└── getInventory()

Everything in PocketMine revolves around methods.

References

https://www.php.net/manual/en/language.oop5.php

Next Chapter

➡ Constructors and Destructors ➡ Access Modifiers ➡ Encapsulation