3v4l.org

run code in 300+ PHP versions simultaneously
<?php session_start(); if (!isset($_SESSION["username"]) && !isset($_SESSION["s1"]) && !isset($_SESSION["s2"])) { header("Location:input.php"); } else { ini_set('display_errors', 'On'); $greeting = "Welcome " .$_SESSION["username"]. ", let's string your strings " .$_SESSION["s1"]. " and " .$_SESSION["s2"]. "!"; if (!isset($_GET["conxy"])) { $conxvar = ""; // function to conx+y with GET and append parameter to URL } else { $conxvar = "The strings x+y have been concatenated: ". $_SESSION["s1"].$_SESSION["s2"]; echo $conxvar; } if (!isset($_GET["conyx"])) { $conyvar = ""; // function to conx+y with GET and append parameter to URL } else { $conyvar = "The strings y+x have been concatenated: ". $_SESSION["s2"].$_SESSION["s1"]; echo $conyvar; } if (!isset($_GET["conyx"])) { $subvar = ""; // function to check substring with GET and append parameter to URL } else { $compareX = strpos($_SESSION["s2"], $_SESSION["s1"]); $compareY = strpos($_SESSION["s1"], $_SESSION["s2"]); if ($compareX !== false) { $subvar = "String ".$_SESSION["s1"]. " is a substring of " .$_SESSION["s2"]; } else { $subvar = "String ".$_SESSION["s1"]. " is NOT a substring of " .$_SESSION["s2"]; } if ($compareY !== false) { $subvar += " and string ".$_SESSION['s2']. " is a substring of " .$_SESSION['s1']; } else { $subvar += " and string ".$_SESSION['s2']. " is NOT a substring of " .$_SESSION['s1']; } echo $subvar; } }
Output for 5.2.3 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.36, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.26, 8.3.0 - 8.3.14, 8.4.1 - 8.4.2
Output for 4.3.2 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.2
Warning: session_start(): Cannot send session cookie - headers already sent in /in/r9lsl on line 3 Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /in/r9lsl:3) in /in/r9lsl on line 3
Output for 4.3.0 - 4.3.1
Warning: session_start() [http://www.php.net/function.session-start]: Cannot send session cookie - headers already sent in /in/r9lsl on line 3 Warning: session_start() [http://www.php.net/function.session-start]: Cannot send session cache limiter - headers already sent (output started at /in/r9lsl:3) in /in/r9lsl on line 3

preferences:
56.77 ms | 409 KiB | 5 Q