Question:What is property overloading? 

Ans: Property overloading continues to protect properties by forcing access and manipulation through public methods, yet allowing the data to be accessed as if it were a public property

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 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:What type of inheritance that PHP supports? 

Ans: In PHP an extended class is always dependent on a single base class that is multiple inheritances is not supported. Classes are extended using the keywords ‘extends’

Question:What are the differences between public, private, protected, static, transient, final and volatile? 

Public: Public declared items can be accessed everywhere.

Protected: Protected limits access to inherited and parent classes (and to the class that defines the item).

Private: Private limits visibility only to the class that defines the item.

Static: A static variable exists only in a local function scope, but it does not lose its value when program execution leaves this scope.

Final: Final keyword prevents child classes from overriding a method by prefixing the definition with final. It means if we define a method with final then it prevent us to override
the method.

transient: A transient variable is a variable that may not be serialized.

volatile: A variable that might be concurrently modified by multiple threads should be declared volatile. Variables declared to be volatile will not be optimized by the compiler because their value can change at any time

Question:What are the abstract class and interface? 

Ans: Abstract class: Abstract classes are the class where one or more methods are abstract but not necessarily all method has to be abstract. Abstract methods are the methods, which are declare in its class but not define. The definition of those methods must be in its extending class.
Interface: Interfaces are one type of class where all the methods are abstract. That means all the methods only declared but no defined. All the methods must be defined by its implemented class.

Question:Define exceptions? 

Ans: An exception is an abnormal condition that arises in a code sequence at run time. Basically there are four important keywords which form the main pillars of exception handling: try, catch, throw and finally.

Question:What is regular expression? 

Ans: The symbolic representation of data is called regular expression. 
The syntax of regular expression is:
Variable_name.method_name(/searching_word/modifiers,”parsed_value”);

Question:How many ways you can write into a file? 

Ans: r+,W, w+, A, a+, X,x+