3v4l.org

run code in 200+ php & hhvm versions
<?php $greeting = "Howdy"; $audience = "World"; echo 'Single-Quote: '; echo '$greeting, $audience'; echo "\n"; echo "Double-Quote: "; echo "$greeting, $audience"; echo "\n"; echo "Special Double-Quote: "; echo "$greeting, {$audience}!";
Output for 4.3.0 - 7.2.6
Single-Quote: $greeting, $audience Double-Quote: Howdy, World Special Double-Quote: Howdy, World!