What are the restrictions when overriding a method ?

Correct Answer: Yes, we can In order to compile a java program, we don't require any main method But to execute a java program we must have a main in it (unless it is an applet or servlet) Because main is the starting point of a java program

Correct Answer: Inheritance is the ability to create new classes based on existing classes It is useful to reuse existing code

Correct Answer: Encapsulation describes the ability of an object to hide its data and methods from the rest of the world

Correct Answer: Java uses sand box security model

Correct Answer: The diamond problem is an ambiguity that can occur when a class multiply inherits from two classes that both descend from a common super class

Correct Answer: Path and Classpath are operating system level environment variales Path is used define where the system can find the executables(exe) files and classpath is used to specify the location class files

Correct Answer: A method declared as final can't be overridden A sub-class can't have the same method signature with a different implementation

Correct Answer: A static initializer block is a block of code that declares with the static keyword It normally contains the block of code that must execute at the time of class loading The static initializer block will execute only once at the time of loading the class only

Correct Answer: When an exception is thrown , the catch block of the try statement are examined in the order in which they appear The first catch block that is capable of handling the exception is executed The remaining catch blocks are ignored

Correct Answer: A thread can be created by subclassing Thread, or by implementing the Runnable interface