Which of these is NOT a PHP class?

Which of these is NOT a PHP class?

• ErrorLog
• DateTime
• PDO
• XMLReader 

 

EXPLANATION

"ErrorLog" is the correct answer.  PHP has a function called "error_log", but it returns true/false and there is no object-oriented version like there is with some of the other classes.
PDO is a PHP extension for working with databases. XMLReader and DateTime are also classes, though they both have procedural versions too.