3v4l.org

run code in 300+ PHP versions simultaneously
<?php $ceu = array( "Italy"=>"Rome", "Luxembourg"=>"Luxembourg", "Belgium"=> "Brussels", "Denmark"=>"Copenhagen", "Finland"=>"Helsinki", "France" => "Paris", "Slovakia"=>"Bratislava", "Slovenia"=>"Ljubljana", "Germany" => "Berlin", "Greece" => "Athens", "Ireland"=>"Dublin", "Netherlands"=>"Amsterdam", "Portugal"=>"Lisbon", "Spain"=>"Madrid", "Sweden"=>"Stockholm", "United Kingdom"=>"London", "Cyprus"=>"Nicosia", "Lithuania"=>"Vilnius", "Czech Republic"=>"Prague", "Estonia"=>"Tallin", "Hungary"=>"Budapest", "Latvia"=>"Riga", "Malta"=>"Valetta", "Austria" => "Vienna", "Poland"=>"Warsaw") ; asort($ceu); foreach ($ceu as $key=>$value) { echo "The capital of $key is $value<br />"; } ?>
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
The capital of Netherlands is Amsterdam<br />The capital of Greece is Athens<br />The capital of Germany is Berlin<br />The capital of Slovakia is Bratislava<br />The capital of Belgium is Brussels<br />The capital of Hungary is Budapest<br />The capital of Denmark is Copenhagen<br />The capital of Ireland is Dublin<br />The capital of Finland is Helsinki<br />The capital of Portugal is Lisbon<br />The capital of Slovenia is Ljubljana<br />The capital of United Kingdom is London<br />The capital of Luxembourg is Luxembourg<br />The capital of Spain is Madrid<br />The capital of Cyprus is Nicosia<br />The capital of France is Paris<br />The capital of Czech Republic is Prague<br />The capital of Latvia is Riga<br />The capital of Italy is Rome<br />The capital of Sweden is Stockholm<br />The capital of Estonia is Tallin<br />The capital of Malta is Valetta<br />The capital of Austria is Vienna<br />The capital of Lithuania is Vilnius<br />The capital of Poland is Warsaw<br />

preferences:
280.88 ms | 407 KiB | 384 Q