<?php
class A
{
function foo()
{
if (isset($this)) {
echo '$this is defined (';
echo get_class($this);
echo ")\n";
} else {
echo "\$this is not defined.\n";
}
}
}
class B
{
function bar()
{
A::foo();
}
}
$a = new A();
$a->foo();
A::foo();
$b = new B();
$b->bar();
B::bar();
?>
Output of the above example in PHP 5:
$this is defined (A)
$this is not defined.
$this is defined (B)
$this is not defined.
Output of the above example in PHP 7:
$this is defined (A)
$this is not defined.
$this is not defined.
$this is not defined.
