Exercise 1: Why is the typecast operator needed to compute the mean in the statement mean = static_cast(float)(total)/value;? What do you think will happen if it is removed? Modify the code and try it. Record what happens. Make sure that you try both even and odd cases. Now put static_cast total back in the program.
LAB 5.3 Working with the for Loop
Bring in
the Pre-lab Reading Assignment). This program has the user input a number n and
then finds the mean of the first n positive integers. The code is shown below:
// This program has the user input a number n and then finds the
// mean of the first n positive integers
// PLACE YOUR NAME HERE
#include <iostream>
using namespace std;
int main()
{
int value; // value is some positive number n
int total = 0; // total holds the sum of the first n positive numbers
int number; // the amount of numbers
float mean; // the average of the first n positive numbers
cout << "Please enter a positive integer" << endl;
cin >> value;
if (value > 0)
{
for (number = 1; number <= value; number++)
{
total = total + number;
} // curly braces are optional since there is only one statement
mean = static_cast<float>(total) / value; // note the use of the typecast
// operator here
cout << "The mean average of the first " << value
<< " positive integers is " << mean << endl;
continues
70 LESSON SET 5 Loops and Files
}
else
cout << "Invalid input - integer must be positive" << endl;
return 0;
}
Exercise 1: Why is the typecast operator needed to compute the mean in the
statement mean = static_cast(float)(total)/value;? What do you think
will happen if it is removed? Modify the code and try it. Record what happens.
Make sure that you try both even and odd cases. Now put static_cast<float>
total back in the program.
Exercise 2: What happens if you enter a float such as 2.99 instead of an integer
for value? Try it and record the results.
Exercise 3: Modify the code so that it computes the mean of the consecutive
positive integers n, n+1, n+2, . . . , m, where the user chooses n and m.
For example, if the user picks 3 and 9, then the program should find the
mean of 3, 4, 5, 6, 7, 8, and 9, which is 6.
Step by step
Solved in 5 steps with 8 images
