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run code in 200+ php & hhvm versions
Bugs & Features
<?php class Test { public $a; protected $have_been_set = array(); public function __set($name, $val) { $this->have_been_set[$name] = TRUE; $this->{$name} = $val; } public function __isset($name) { print "checking for $name\n"; return array_key_exists($name, $this->have_been_set); } } $t1 = new Test(); $t1->a = null; $t2 = new Test(); var_dump( isSet($t1->a), isSet($t2->a) );
based on jg0re
Output for 5.3.19 - 7.2.0
bool(false) bool(false)