1.3 Labworks  (Page 8/11)

• the constructor which assigns the initial values 0 to all data members of each Cstudent objects.
• A function to get a student-id-number.
• A function to get one grade and update the total of the entered grades.
• A function to compute the average of all entered grades of a student.
• A function to display student-id-number, and the average grade of that student.Include the class CStudent in a complete C++ program. This program creates one CStudent object, inputs the data for the object and displays the object’s data to verify the workings of the member functions.

2.7 ) Test the following program which uses a run-time allocated array.

#include<iostream.h>

void main()

{

int num;

cout<<“Please enter the numbers of input: ”

cin>>num;

int a = new int [num];

int total = 0; // Holds total of user’s eight numbers.

int ctr;

for (ctr=0; ctr<num; ctr++)

{

cout<<“Please enter the next number...”;

cin>>a[ctr];

total += a[ctr];

}

cout<<“The total of the numbers is “<<total<<“\n”;

return;

delete [] a;

}

2.8) Given a class named IntArray that contains two private data members: a pointer to the beginning of the array, and an integer representing the size of the array. The public functions include a constructor and member functions that show every element in the IntArray, and show the first IntArray element only. The definition of the class IntArray is as follows:

// IntArray.h

class IntArray

{

private:

int* data; //pointer to the integer array

int size;

public:

IntArray(int* d, int s);

void showList();

void showFirst( );

};

// IntArray.cpp

IntArray::IntArray(int* d, int s)

{

data = d;

size = s;

}

void IntArray::showList()

{

cout<<"Entire list:"<<endl;

for(int x = 0; x<size; x++)

cout<<data[x]<<endl;

cout<<"----------------------"<<endl;

}

void IntArray::showFirst()

{

cout<<"First element is ";

cout<<data[0]<<endl;

}

a. Add to the class IntArray one more member function named findMax which returns the largest element in the array.

b. Write a main program that instantiates one array of integers and then displays the array, the first element and the largest element of the array.

Lab session 9: object manipulation

1. objective

The objectives of Lab session 9 are (1) to learn to write parameterized constructor, constructor with default arguments and (2) to practice destructors.

2. experiment

2.1) Run the following program in a C++ environment.

class Int{

private:

int idata;

public:

Int(){

idata=0;

cout<<"default constructor is called"<<endl;

}

Int(int d=9){

idata=d;

cout<<"constructor with argument is called"<<endl;

}

void showData(){

cout<<"value of idata: "<<idata<<endl;

}

};

void main()

{

Int i;

Int j(8);

Int k=10;

}

a. Explain why the program incurs a compile-time error.

b. Modify the program in order to remove the above error. Run the modified program.

2.2) Run the following program in a C++ environment.

class Vector{

private:

int *value;

int dimension;

public:

Vector(int d=0){

dimension=d;

if (dimension==0)

value=NULL;

else{

value=new int[dimension];

for (int i=0; i<dimension; i++)

value[i]=0;

}

}

void showdata(){

for (int i=0; i<dimension; i++)

cout<<value[i];

cout<<endl;