3v4l.org

run code in 300+ PHP versions simultaneously
<?php class foo { function __construct() { $this->a = "hello"; $this->b = "hi"; $this->val = "howdy"; $val = "a"; echo $this->{$val}; // outputs "hello" echo "\n"; $val = "b"; echo $this->${val}; // outputs "hi" echo "\n"; echo $this->val; //outputs "howdy" echo "\n"; echo $this->{"val"}; } } $foo = new foo();
Output for 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Deprecated: Creation of dynamic property foo::$a is deprecated in /in/n8jEZ on line 5 Deprecated: Creation of dynamic property foo::$b is deprecated in /in/n8jEZ on line 6 Deprecated: Creation of dynamic property foo::$val is deprecated in /in/n8jEZ on line 7 hello Fatal error: Uncaught Error: Undefined constant "val" in /in/n8jEZ:15 Stack trace: #0 /in/n8jEZ(26): foo->__construct() #1 {main} thrown in /in/n8jEZ on line 15
Process exited with code 255.
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28
hello Fatal error: Uncaught Error: Undefined constant "val" in /in/n8jEZ:15 Stack trace: #0 /in/n8jEZ(26): foo->__construct() #1 {main} thrown in /in/n8jEZ on line 15
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33
hello Warning: Use of undefined constant val - assumed 'val' (this will throw an Error in a future version of PHP) in /in/n8jEZ on line 15 hi howdy howdy
Output for 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20
hello Notice: Use of undefined constant val - assumed 'val' in /in/n8jEZ on line 15 hi howdy howdy
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