What is JAR file? what are the main uses of JAR files?

Correct Answer: Unwrapping is also called as unpacking or unboxing Getting the private data stored in the object by using methods is called unpacking or unwrapping

Correct Answer: Wrapping is also called as packing or boxing Storing the data inside the object as private data which can accessed outside the class only by using methods

Correct Answer: String class objects are immutable objects and they represents strings( sequence of characters) StringBuffer class objects are mutable objects representing strings and they are Thread safe StringBuild class objects are also mutable objects representing strings and they are not Thread safe

Correct Answer: new ClassName( arg1, arg2, argN); Ex: Class sample { Sample(int a) { Systemoutprintln("arg con a =" +a); } } class Demo { Public static void main( String[] args) { Sample s1= new Sample(23); Sample s2= new Sample(45); } }

Correct Answer: Constructor is not a special method Constructor is block of code that is executed automatically whenever object of the class is created

Correct Answer: Path contains path of exe files(commands) Classpath contains path of packages packages can be stored in folder or jar files

Correct Answer: By using super call we can call super class constructors from sub class constructors and we can initialize super class private data

Correct Answer: yes if the method is ovreriding method no if the method is not overriding method

Correct Answer: - By using method overriding a sub class can change the definition of super class method - By using overriding a sub class can modify the functionality of the super class

Correct Answer: By using overloading we can add new functionality to the sub class