Classes and properties

A class is a blueprint for objects. class User { ... } declares the type. Create an instance with new User() — that expression returns an object of that class.

Properties hold per-object state. public string $name; declares a typed public property (PHP 7.4+ typed properties; PHP 8.x is the Easy target). Assign with $user->name = "Ada"; — the arrow -> reaches into the object.

Inside a method, $this refers to the current instance. $this->name reads or writes that object's property. Outside the class, use the variable that holds the object: $user->name.

Methods are functions declared inside the class: public function greet(): void { echo $this->name; }. Call them with $user->greet();. Visibility defaults matter later; start with public so callers can use the API.

Misses: writing user.name like JavaScript without ->, forgetting $ on $this, treating the class name as an already-built object without new, or assigning undeclared dynamic properties when you meant a declared typed property.

<?php
class User {
    public string $name;

    public function greet(): void {
        echo "hi " . $this->name . "\n";
    }
}

$user = new User();
$user->name = "Ada";
$user->greet();