Kas ir redzamības modifikatori PHP?

Redzamības modifikatori (public, protected, private) nosaka piekļuves līmeni pie klases īpašībām un metodēm.

• public - pieejams no jebkuras vietas (klases iekšpusē, mantojošās klasēs, ārpus tās).
• protected - pieejams klases iekšpusē un mantojošās klasēs.
• private - pieejams tikai tajā klasē, kurā tas ir definēts.

Piemērs:

<?php

class MyClass {
    public $publicProperty = 'public';
    protected $protectedProperty = 'protected';
    private $privateProperty = 'private';

    public function publicMethod() {
        echo "Public method access: " . $this->publicProperty . ", " . $this->protectedProperty . ", " . $this->privateProperty . "\n";
    }

    protected function protectedMethod() {
        echo "Protected method access: " . $this->publicProperty . ", " . $this->protectedProperty . ", " . $this->privateProperty . "\n";
    }

    private function privateMethod() {
        echo "Private method access: " . $this->publicProperty . ", " . $this->protectedProperty . ", " . $this->privateProperty . "\n";
    }
}

class MyChildClass extends MyClass {
    public function testAccess() {
        echo "Child class access: " . $this->publicProperty . ", " . $this->protectedProperty . "\n"; // piekļuve public un protected
        // echo $this->privateProperty; // kļūda, private nepieejams
        $this->publicMethod();
        $this->protectedMethod();
        // $this->privateMethod(); // kļūda, private nepieejams
    }
}

$obj = new MyClass();
echo $obj->publicProperty . "\n"; // pieejams
// echo $obj->protectedProperty; // kļūda, protected nepieejams ārpus klases
// echo $obj->privateProperty; // kļūda, private nepieejams ārpus klases
$obj->publicMethod();
// $obj->protectedMethod(); // kļūda, protected nepieejams ārpus klases
// $obj->privateMethod(); // kļūda, private nepieejams ārpus klases

$childObj = new MyChildClass();
$childObj->testAccess();