Internal Static Call

<?php

class a {
    function foo() {
        echo __METHOD__ . PHP_EOL;
    }
}

class b extends a {}
class c extends b {
    function bar() {
        $this::foo();
        $this->foo();
        a::foo();
        b::foo();
        c::foo();
        d::foo();
        static::foo();
        self::foo();
        parent::foo();
    }
}

class d extends c {}

(new c)->bar();

Trap of the day: one of the calls in bar() generates a ‘Non-static method a::foo() cannot be called statically’ error.

Which one? It is the d::foo(). All other calls are made within the C class : internal calls may use static or normal syntax, while external calls must use the correct call syntax. This allows calls like ‘parent::__construct()’.

When the call to bar() is made with ‘(new d)’, the ‘d::foo()’ works again.

See Also

• Late Static Bindings (PHP manual)

• Internal Static Call [Try me]

PHP Error Messages

• Non-static method a::foo() cannot be called statically

PHP Features

• static

• class

Last updated: 14 July 2026