Exercise 5.4 (Completed)

1. (Program) a. Using a do-while statement, write, compile, and run a C++ program to accept
a grade. The program should request a grade continuously as long as an invalid grade is
entered. An invalid grade is any grade less than 0 or greater than 100. After a valid grade has
been entered, your program should display the value of the grade entered.

#include <iostream>
using namespace std;
int main()
{
	int grade;
	do{
		cout << "Enter your grade" << endl;
			cin >> grade;
		if (grade > 0 && grade <= 100){
			cout << grade;
		}
	
	} while (grade > 100 || grade < 0);
	

	system("PAUSE");
	return 0;
}

b. Modify the program written for Exercise 1a so that the user is alerted when an invalid grade
has been entered.

#include <iostream>
using namespace std;
int main()
{
	int grade;
	do{
		cout << "Enter your grade" << endl;
			cin >> grade;
		if (grade > 0 && grade <= 100){
			cout << grade;
		}
		else{ cout << "invalid number" << endl; }
	
	} while (grade > 100 || grade < 0);
	

	system("PAUSE");
	return 0;
}

c. Modify the program written for Exercise 1b so that it allows the user to exit the program by
entering the number 999.

#include <iostream>
using namespace std;
int main()
{
	int grade;
	do{
		cout << "Enter your grade" << endl;
			cin >> grade;
		if (grade > 0 && grade <= 100){
			cout << grade;
		}
		else if (grade == 999){
			grade = 10;
		}
		else{ cout << "invalid number" << endl; }
	
	} while (grade > 100 || grade < 0);
	

	system("PAUSE");
	return 0;
}

d. Modify the program written for Exercise 1b so that it automatically terminates after five
invalid grades are entered.

#include <iostream>
using namespace std;
int main()

{
	int grade;
	do{
		for (int i = 1; i <= 5; i++){
			cout << "Enter your grade" << endl;
			cin >> grade;
			if (grade > 0 && grade <= 100){
				cout << grade;
			}
			else if (i >= 5){
				grade = 20;
			}
			else{ cout << "invalid number" << endl; }
		}
	} while (grade > 100 || grade < 0);
	

	system("PAUSE");
	return 0;
}
2. (Program) a. Write, compile, and run a C++ program that continuously requests a grade to be
entered. If the grade is less than 0 or greater than 100, your program should print a message
informing the user that an invalid grade has been entered; else, the grade should be added to

a total. When a grade of 999 is entered, the program should exit the repetition loop and compute
and display the average of the valid grades entered.

#include <iostream>
using namespace std;
int main()
{
	int grade,total =0;
	do{
		for (int i = 1; i <= 5; i++){
			cout << "Enter your grade" << endl;
			cin >> grade;
			if (grade > 0 && grade <= 100){
				total = total + grade;
				cout << total << endl;
			}
			else if ( grade == 999){
				grade = 20;
			}
			else{ cout << "invalid number" << endl; }
		}
	} while (true);
	

	system("PAUSE");
	return 0;
}

b. Run the program written in Exercise 2a on a computer and verify the program by using
appropriate test data.
Done!!
3. (Program) a. Write, compile, and run a C++ program to reverse the digits of a positive integer
number. For example, if the number 8735 is entered, the number displayed should be 5378.
(Hint : Use a do-while statement and continuously strip off and display the number’s units
digit. If the variable num initially contains the number entered, the units digit is obtained as
(num % 10)). After a units digit is displayed, dividing the number by 10 sets up the number
for the next iteration. Therefore, (8735 % 10) is 5 and (8735 / 10) is 873. The do-while
statement should continue as long as the remaining number is not 0.

#include <iostream>
using namespace std;
int main()
{
	int num,rev;
	cout << "Enter your number to reverse" << endl;
	cin >> num;
	do{
		
		rev =(num % 10);
		cout << rev;
		num = (num / 10);
	} while (num !=0);
	

	system("PAUSE");
	return 0;
}

b. Run the program written in Exercise 3a on a computer and verify the program by using
appropriate test data.

Done!!

4. (Practice) Repeat any of the exercises in Section 5.3, using a do-while statement rather than
a for statement.
#include <iostream>
using namespace std;
int main(){
	double money = 1000;

	for (double year= 1; year <= 10; year++){

		money = money + .03 * money;

		cout << money<< '\n';
		
		}
retur 0;
	}
-------------Exercise for Section 5.3 Conversion------------------------------

#include <iostream>
using namespace std;
int main()
{
	double money = 1000;
	int year = 1;

	do{
		money = money + .03 * money;
		cout << money << '\n';
		year++;
		
	} while (year <= 10);

	system("PAUSE");
	return 0;
}