Question

Write a C++ program that keeps asking user to enter a positive integer number until a sentinel value (999) is entered.

Then for each positive number entered by the user, find out how many digits it consists. (Hint: divide a number by 10 will remove one digit from the number. You can count how many divisions it needs to bring the number to 0.)

An example of executing such a program is shown below. Note that the user input is in italic font.

Enter 999 to end this program.
Please enter a positive integer number: 1984
There are 4 digits in the number you just entered.

Enter 999 to end this program.
Please enter a positive integer number: -98
It must be a positive value.
Please enter a positive integer number: -8
It must be a positive value.
Please enter a positive integer number: 0
It must be a positive value.
Please enter a positive integer number: 6856298
There are 7 digits in the number you just entered.

Enter 999 to end this program.
Please enter a positive integer number: -9
It must be a positive value.
Please enter a positive integer number: 999
Bye!

In this program, you can safely assume that user will always enter the integer values for input.

Answer 1

C++ code:

#include <iostream>
using namespace std;
int main()
{
    //initializing nuumber and count
    int num,count;
    //asking to enter 999 to end program
    cout<<"Enter 999 to end this program."<<endl;
    //asking for positive integer
    cout<<"Please enter a positive integer number: ";
    //accepting it
    cin>>num;
    //looping till user enter 999
    while(num!=999){
        //checking if the number is less than or equal to 0
        if(num<=0)
            //printing it must be positive value
            cout<<"It must be a positive value."<<endl;
        else{
            //initializing count as 0
            count=0;
            //looping till number is 0
            while(num!=0){
                //incrementing count
                count++;
                //dividing number by 10
                num/=10;
            }
            //printing number of digits
            cout<<"There are "<<count<<" digits in the number you just entered."<<endl;
            //asking to enter 999 to end program
            cout<<"\nEnter 999 to end this program."<<endl;
        }
        //asking for positive integer
        cout<<"Please enter a positive integer number: ";
        //accepting it
        cin>>num;
    }
    //printing Bye
    cout<<"Bye!"<<endl;
    return 0;
}

Screenshot:

Input and Output: