3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo { public $bar; } $foo = new Foo; $arr = array("", " ", FALSE, TRUE, array(), NULL, "0", 0, 0.0, new stdClass, $foo, $foo->bar, "\0"); define('PAD', 20); $headings = array('type', 'if', 'isset', 'empty', 'is_null'); // foreach($headings as $heading){ echo str_pad($heading, PAD), " | "; } echo "\n"; $x = str_pad("TRUE", PAD) . " | "; $y = str_pad("", PAD) . " | "; foreach($arr as $val){ $a = debug_zval_dump($val); var_dump($a); /* echo str_pad(print($val), PAD), " | "; echo $val ? $x : $y; echo isset($val) ? $x : $y; echo empty($val) ? $x : $y; echo is_null($val) ? $x : $y; */ echo "\n"; }
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
string(0) "" interned NULL string(1) " " interned NULL bool(false) NULL bool(true) NULL array(0) interned { } NULL NULL NULL string(1) "0" interned NULL int(0) NULL float(0) NULL object(stdClass)#2 (0) refcount(3){ } NULL object(Foo)#1 (1) refcount(4){ ["bar"]=> NULL } NULL NULL NULL string(1) "" interned NULL
Output for 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30
string(0) "" refcount(1) NULL string(1) " " refcount(1) NULL bool(false) NULL bool(true) NULL array(0) refcount(1){ } NULL NULL NULL string(1) "0" refcount(1) NULL int(0) NULL float(0) NULL object(stdClass)#2 (0) refcount(3){ } NULL object(Foo)#1 (1) refcount(4){ ["bar"]=> NULL } NULL NULL NULL string(1) "" refcount(1) NULL
Output for 7.1.0, 7.1.7 - 7.1.20, 7.2.0 - 7.2.33
string(0) "" refcount(1) NULL string(1) " " refcount(1) NULL bool(false) NULL bool(true) NULL array(0) refcount(4){ } NULL NULL NULL string(1) "0" refcount(1) NULL int(0) NULL float(0) NULL object(stdClass)#2 (0) refcount(3){ } NULL object(Foo)#1 (1) refcount(4){ ["bar"]=> NULL } NULL NULL NULL string(1) "" refcount(1) NULL
Output for 7.1.5 - 7.1.6
string(0) "" refcount(4) NULL string(1) " " refcount(4) NULL bool(false) NULL bool(true) NULL array(0) refcount(4){ } NULL NULL NULL string(1) "0" refcount(4) NULL int(0) NULL float(0) NULL object(stdClass)#2 (0) refcount(3){ } NULL object(Foo)#1 (1) refcount(4){ ["bar"]=> NULL } NULL NULL NULL string(1) "" refcount(4) NULL
Output for 7.0.0 - 7.0.20
string(0) "" refcount(1) NULL string(1) " " refcount(1) NULL bool(false) NULL bool(true) NULL array(0) refcount(3){ } NULL NULL NULL string(1) "0" refcount(1) NULL int(0) NULL float(0) NULL object(stdClass)#2 (0) refcount(3){ } NULL object(Foo)#1 (1) refcount(4){ ["bar"]=> NULL } NULL NULL NULL string(1) "" refcount(1) NULL
Output for 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28
string(0) "" refcount(3) NULL string(1) " " refcount(3) NULL bool(false) refcount(3) NULL bool(true) refcount(3) NULL array(0) refcount(3){ } NULL NULL refcount(3) NULL string(1) "0" refcount(3) NULL long(0) refcount(3) NULL double(0) refcount(3) NULL object(stdClass)#2 (0) refcount(3){ } NULL object(Foo)#1 (1) refcount(4){ ["bar"]=> NULL refcount(3) } NULL NULL refcount(5) NULL string(1) "" refcount(3) NULL
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