Understanding the static Keyword in PHP with Use Cases

The static keyword in PHP is used in three main ways:

1. Static Variables in Functions

Static variables retain their values between function calls.

function counter() {
    static $count = 0;
    $count++;
    echo $count;
}

Each call to counter() will increment the same $count.

2. Static Properties and Methods

Used when you want to access class members without creating an object.

class Math {
    public static $pi = 3.14;

    public static function getPi() {
        return self::$pi;
    }
}

echo Math::getPi(); // 3.14

3. Late Static Binding

static:: respects the runtime (called) class, unlike self::, which uses the defining class.

class ParentClass {
    protected static function who() {
        echo "Parent\n";
    }
    public static function test() {
        static::who(); // Late static binding
    }
}
class ChildClass extends ParentClass {
    protected static function who() {
        echo "Child\n";
    }
}
ChildClass::test(); // Outputs: Child

self:: vs static::

• self:: = early binding (class where method is defined).
• static:: = late binding (class that was called).

Use static:: when working with inheritance and overridden methods.

Conclusion:

The static keyword is versatile in PHP, helping manage memory in functions, class-level utilities, and polymorphic behavior in OOP.

Happy Coding! 😊