__get and __set for property access in PHP

Introduction

These magic methods let you control what happens when you read or write properties that don't exist or are not accessible in an object.

You want to handle reading a property that is private or missing without errors.

You want to control or customize what happens when someone sets a property value.

You want to create flexible objects that can store data dynamically.

You want to add logging or validation when properties are accessed or changed.

Syntax

PHP

public function __get(string $name) {
    // code to return a value for $name
}

public function __set(string $name, $value): void {
    // code to set $value for $name
}

__get is called automatically when reading a property that is not accessible.

__set is called automatically when writing to a property that is not accessible.

Examples

This example stores unknown properties in an internal array and retrieves them.

PHP

<?php
class Example {
    private $data = [];

    public function __get(string $name) {
        return $this->data[$name] ?? null;
    }

    public function __set(string $name, $value): void {
        $this->data[$name] = $value;
    }
}

$obj = new Example();
$obj->color = 'red';
echo $obj->color;
?>

This example uses __get and __set to access a private property safely.

PHP

<?php
class Person {
    private $name = 'Alice';

    public function __get(string $name) {
        if ($name === 'name') {
            return $this->name;
        }
        return null;
    }

    public function __set(string $name, $value): void {
        if ($name === 'name') {
            $this->name = $value;
        }
    }
}

$p = new Person();
echo $p->name; // reads private property via __get
$p->name = 'Bob'; // sets private property via __set
echo $p->name;

Sample Program

This program shows how __get and __set work by printing messages when properties are accessed or set. It stores values in an internal array.

PHP

<?php
class MagicBox {
    private $items = [];

    public function __get(string $key) {
        echo "Getting '$key'\n";
        return $this->items[$key] ?? 'Not found';
    }

    public function __set(string $key, $value): void {
        echo "Setting '$key' to '$value'\n";
        $this->items[$key] = $value;
    }
}

$box = new MagicBox();
$box->fruit = 'apple';
echo $box->fruit . "\n";
echo $box->vegetable . "\n";

Important Notes

If you try to access a property that exists and is public, __get and __set are not called.

Use __get and __set carefully because they can hide bugs if properties are misspelled.

Summary

__get and __set let you control reading and writing of inaccessible or missing properties.

They help make flexible and dynamic objects.

Remember to handle missing properties gracefully inside these methods.