Object Oriented Programming : Practice Questions and Answers

The private members can access any standard input or output. There is no restriction on access to any input or output stream. And since standard input can also be used hence only accessing the output stream is not true.

The reason given in option “No, because main function is user defined” is wrong. The proper reason that the main function should not be private is that it should be accessible in whole program. This makes the program flexible.

The private members access from outside the class produce an error. The error states that the code at some line can’t access the private members. And denies the access terminating the program.

If private functions get accessed even by the parent class that will violate the rules of private members. If the functions can be accessed then the derived class security is hindered.

The private member functions can be accessed within the class. A public member function can be called which in turn calls the private member function. This maintains the security and adheres to the rules of private members.

The protected members are available within the class. And are also available in derived classes. But these members are treated as private members for outside the class and inheritance structure. Hence can’t be accessed.

The nested class members can’t be accessed in the enclosed class even though other members can be accessed. This is to ensure the class members security and not to go against the rules of private members.

Even the private member functions can be called outside the class. This is possible if address of the function is known. We can use the address to call the function outside the class.

There are no conditions applied on the number of private member functions that can be declared in a class. Though the system may restrict use of too many functions depending on memory.

The private keyword must be mentioned before each private member. Unlike the rule in C++ to specify private once and list all other private member’s, in java all member declarations must be preceded by the keyword private.

The private members doesn’t have to have the keyword with each private member. We only have to specify the keyword private followed by single colon and then private member’s are listed.

The function declaration must contain private keyword follower by the return type and function name. Private keyword is followed by normal function declaration.

The private member functions can never be accessed in the derived classes. The access specifiers is of maximum security that allows only the members of self class to access the private member functions.

The private members are accessible within the class. There is no restriction on use of private members by public or protected members. All the members can access the private member functions of the class.

The member functions can be accessed inside the class only if they are private. The access is scope is limited to ensure the security of the private members and their usage.

The copy constructor is used to copy the values from one object to other. Pass by values is not same as copy constructor method. Actually the pass by value method uses a copy constructor to copy the values in a local object.

There can’t be more than one variable or object with the same name in same scope. The scope is same, since the object is passed, it becomes local to function and hence function can’t have one more object of same name.

A copy of all the values is created. If the constructor is called, there will be a compile time error or memory shortage. This happens because each time a constructor is called, it try to call itself again and that goes infinite times.

There is no limit to how many objects can be passed. This works in same way as that any other variable gets passed. Array and object can be passed at same time also.

Having the address being passed to the function, the changes are automatically made to the main function. In all the cases if the address is being used, the same memory location will be updated with new values.