Bug #79689 [NEW]: Casting a non-existent array index to int returns 0 instead of null

From: sebastian dot awatramani at gmail dot com Operating system: Linux Mint 19 PHP version: 7.4Git-2020-06-11 (Git) Package: Unknown/Other Function Bug Type: Bug Bug description:Casting a non-existent array index to int returns 0 instead of null Description: ------------ Using the null coalesce operator while casting a result to int, I expect that if the array index I'm trying to assign doesn't exist, it should fail and then move on to the next part of the NC statement, like so: $a = (int) $_GET['field'] ?? null If there is no $_GET['field'] nor a $_GET in general, I expect $a to equal null. But instead $a ends up as 0 because casting a non-existent array index to int returns the int val of false Test script: --------------- $a = (int) $_GET['field'] ?? null Expected result: ---------------- $a === null Actual result: -------------- $a === 0 -- Edit bug report at https://bugs.php.net/bug.php?id=79689&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=79689&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=79689&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=79689&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=79689&r=needscript Try newer version: https://bugs.php.net/fix.php?id=79689&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=79689&r=support Expected behavior: https://bugs.php.net/fix.php?id=79689&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=79689&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=79689&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=79689&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=79689&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=79689&r=dst IIS Stability: https://bugs.php.net/fix.php?id=79689&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=79689&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=79689&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=79689&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=79689&r=mysqlcfg