Warning: Undefined array key "library" in C:\xampp\htdocs\School\cis222\h4\hw4-2.php on line 2

Warning: foreach() argument must be of type array|object, null given in C:\xampp\htdocs\School\cis222\h4\hw4-2.php on line 4



Fatal error: Uncaught TypeError: natcasesort(): Argument #1 ($array) must be of type array, null given in C:\xampp\htdocs\School\cis222\h4\hw4-2.php:9 Stack trace: #0 C:\xampp\htdocs\School\cis222\h4\hw4-2.php(9): natcasesort(NULL) #1 {main} thrown in C:\xampp\htdocs\School\cis222\h4\hw4-2.php on line 9