Question:What does $GLOBALS means?
$GLOBALS is associative array including references to all variables which are currently defined in the global scope of the script.
Question:What are the advantages of object-oriented programming?
a. Simplicity
b. Modifiability
c. Re-usability.
d. Extensibility
e. Catch errors at compile time rather than at runtime
f. Reduce large problems to smaller
Question:What does $_SERVER means?
$_SERVER is an array including information created by the web server such as paths, headers, and script locations.
Question:What is object cloning?
Ans: It is difficult to copy an object, because all objects are treated as references rather than as values. If we try to copy a referenced object, it will simply point back to the addressing location of the original object. To remedy the problems with copying, PHP offers an explicit means for cloning an object is known as object cloning.
Question:How can we determine whether a variable is set?
The boolean function isset determines if a variable is set and is not NULL.