Question

c++ language

I am trying to practice user validation, as in if I enter a letter instead of a number, I get a 0 for the output, can someone look at my code and tell me how to fix it

char firstInital, lastInitial;
   int userAge;
   std::cout << "Program 1-2: Get user initials and age in days\n ";
   std::cout << "-----------------------------------------------\n\n ";
       std::cout << "Please enter the first letter of your first name: ";
       std::cin >> firstInital;
       std::cout << "Please enter the first letter of your last name: ";
       std::cin >> lastInitial;

       std::cout << " Hello " << firstInital << " " << lastInitial << " Please enter your age in years: ";
       std::cin >> userAge;
       while (!(cin >> userAge))
       {
           cin.clear();
           while (cin.get() != '\n') continue;
           std::cout << " Error, age must be a positive integer only, please try again: ";

       }
       std::cout << firstInital << " " << lastInitial << " You are " << userAge << " years old, which means you are at least "
           << userAge * 365 << " days old!";
  
   std::cout << "Press any key to exit." << endl;

2nd part:

int myArray[5];
   for (int i = 0; i < 5; i++)
   {
       std::cout << "Please enter a number for the array: ";
       std::cin >> myArray[i];
       while (!(cin >> myArray[i]))
       {
           std::cout << " Invalid entry, please try again: ";
           cin.clear();
           cin.ignore(100, '\n');
       }
   }
   for (int i = 0; i < 5; i++)
       std::cout << myArray[i] << " ";

Answer 1

Hey,

Below is the edited code to your question

#include<iostream>
#include <sstream>
using namespace std;
int check(string s)
{
for(int i=0;i<s.length();i++)
{
if(s[i]<48||s[i]>57)
return 0;
}
return 1;
}
int main()
{
char firstInital, lastInitial;
int userAge;
string age;
std::cout << "Program 1-2: Get user initials and age in days ";
std::cout << "------------------------------------------------------------------------- ";

std::cout << "Please enter the first letter of your first name: " << flush;
std::cin >> firstInital;
std::cout << "Please enter the first letter of your last name: ";
std::cin >> lastInitial;

std::cout <<"Hello "<< firstInital << lastInitial << " Please enter your age in years: ";
std::cin >> age;

while (check(age)==0)
{

std::cout << " Invalid input, please enter only positive integers and try again: ";
cin >> age;

}
stringstream g(age);
g>>userAge;

std::cout << firstInital << lastInitial << " You are " << userAge << " years old, which means that you are at least "
<< userAge * 365 << " days old! ";
}

2)

#include<iostream>
#include <sstream>
using namespace std;
int check(string s)
{
for(int i=0;i<s.length();i++)
{
if(s[i]<48||s[i]>57)
return 0;
}
return 1;
}
int main()
{
int myArray[5];
for (int i = 0; i < 5; i++)
{
std::cout << "Please enter a number for the array: ";
string num;
cin>>num;
while (check(num)==0)
{

std::cout << " Invalid input, please enter only integers and try again: ";
cin >> num;

}
stringstream g(num);
g>>myArray[i];
}
for (int i = 0; i < 5; i++)
std::cout << myArray[i] << " ";
}

Kindly revert for any queries

Thanks.