CS304 Midterm Past Paper 4

CS304 Object Oriented Programming · Mid Term Examination – Spring 2005 · Time Allowed: 90 Minutes

d. All coding questions should be answered using the C ++ syntax.

You are allowed to use the Dev-C++ compiler to write and test your code. If you do so please remember to copy and paste your code into the examination

Total Marks: 40 Total Questions: 3

Q1. Design and implement a String class that makes the following code work properly. The class should store the string in a dynamically allocated memory.

int main()

String X, Y = " World!"; X = " Hello " + Y; cout<< X << endl; return 0;

XYZ *this;

b)

1. Assignment of private data members at the time of object creation. 2. When an object is passed by vale to a function. 3. When allocating memory dynamically we use copy constructor to avoid dangling pointer issue.

Q3. class Complex

private:

double x,y; static int z;

public:

Complex(double = 0.0); friend ostream& operator<<(ostream&, const Complex&); static int doSomething( ) { z = 2 * y; return z; }

a. What is wrong in the definition of member function doSomething( ). 03

Answer: Static keyword because using static key word we are declaring a static member function doSomething(). Which can not use non static data members. b. What will be the effect of writing the friend function operator<<(…) in private part of the above class? 02

Answer: There will be no effect on friend function if we write it in private part. Friend function is a friend function and can use any private or public data member of the class. Where ever we declare it in class body.