Question

#include <iostream>
#include <string>
using namespace std;

int main() {

double age;
double months;
string name;

months = age*12.0;

cout << "Enter your name and age: ";
cin >> name >> age;
cout << "Hello " << name << " age " << age << " (" << months << " months)\n";

return(0);
}

The program asks for name and age, and should out put the name and age in a sentence with the age in months in parentheses.
Output gives something like:
Hello Bob age 20 (1.82561e-313 months), but should be Hello Bob age 20 (240 months). I did not use int because I wanted to be able to input non int values for age.
I have tried 12 instead of 12.0 and tried declaring a variable and doing months = age*m where m = 12.0 but is result is the same. By the way, the random value is about the same regardless of what variable age is. Why is this happening? Also, would this be a link-time error or run-time error?

Answer 1

You’re doing the multiplication using age before it’s initialized. What value would you expect it to give you?

Change your code to first get the age, and then do the multiplication:

cout << "Enter your name and age: ";
cin >> name >> age;
months = age*12.0;

cout << "Hello " << name << " age " << age << " (" << months << " months)\n";