21. The r+ mode of the fopen() function opens a file for reading or writing, maintains exiting content, and places the file pointer at the beginning of the file. Answer: C.
22. The copy() function can be used to copy a file. Answer: A.
23. To set a cookie to expire 24 hours from now, compute the number of seconds and use the time() function: $cookie_expire = time() +86400. Answer: C.
24. The semicolon character (;) is used as a statement terminator to indicate the end of a PHP command. Answer: D.
25. The command $days = array(); will initialize the $days array. Answer: B.
26. The file_exists() function can be used to see if a file by the given name is already in existence. Answer: D.
27. The value of $_COOKIE[user] is equal to what was set in the cookie. Answer: C.
28. The array_merge() function should be used to combine two or more existing arrays. Answer: B.
29. The function to use is session_start()
30. After opening a file with the fopen() function, fclose() is used to close the file pointer. Answer: A.
31. The gettype function can be used to show the data type for a variable. Answer: B.
32. The rmdir() function removes a directory from a file system. Answer: A.
33. sleep() accepts seconds and usleep() accepts milliseconds. Answer: B.
34. The sizeof() function can tell how many elements are in an array Answer: D.
35. Information about a session, by default, is configured in the PHP configuration file to be saved beneath /tmp. Answer: C.
36. $_ENV contains variables provided to a script by means of the server environment. Answer: D.
37. The unlink() function can be used to delete a file. Answer: C.
