Validating User Input in C++

1#include <iostream>
2#include <limits>
3
4int main(){
5  int userAge;
6
7  while (true) {
8    std::cout << "Enter your age: ";
9    std::cin >> userAge;
10
11    if (std::cin.fail()) {
12      std::cin.clear(); // Clear error flags
13      std::cin.ignore(
14        std::numeric_limits<
15          std::streamsize>::max(),
16        '\n'); 
17      std::cout
18        << "Invalid input. Please enter a number.\n";
19    } else if (userAge <= 0 || userAge > 120) {
20      std::cout <<
21        "Age must be between 1 and 120.\n";
22    } else {
23      break; // Valid input, exit loop
24    }
25  }
26
27  std::cout << "Your age is: " << userAge;
28}

1#include <iostream>
2#include <string>
3#include <stdexcept>
4
5int main(){
6  std::string input;
7  int userAge;
8
9  while (true) {
10    std::cout << "Enter your age: ";
11    std::getline(std::cin, input);
12
13    try {
14      userAge = std::stoi(input); 
15      if (userAge <= 0 || userAge > 120) {
16        throw std::out_of_range(
17          "Age out of valid range");
18      }
19      break; // Valid input, exit loop
20    }
21    catch (const std::invalid_argument&) {
22      std::cout
23        << "Invalid input. Please enter a number.\n";
24    } catch (const std::out_of_range&) {
25      std::cout <<
26        "Age must be between 1 and 120.\n";
27    }
28  }
29
30  std::cout << "Your age is: " << userAge;
31}