What is the difference between public, private, and protected?

Question

When and why should I use public, private, and protected functions and variables inside a class? What is the difference between them?

Examples:

// Public public $variable; public function doSomething() {   // ... }  // Private private $variable; private function doSomething() {   // ... }  // Protected protected $variable; protected function doSomething() {   // ... } 

Answer 1

You use:

• public scope to make that property/method available from anywhere, other classes and instances of the object.

• private scope when you want your property/method to be visible in its own class only.

• protected scope when you want to make your property/method visible in all classes that extend current class including the parent class.

If you don't use any visibility modifier, the property / method will be public.

More: (For comprehensive information)

• PHP Manual - Visibility