The program is just simply supposed to calculate the users age by subtracting their dob from the current year. When I run the program it compiles successfully but I get a long number such as -215863352. The if and else conditions are added just to test them out, I was writing various programs using them to make sure I understand the syntax in c. I figure I'm missing something simple but can't figure it out.

#include <stdio.h>
int main()
{
    int year;
    int cyear;
    int age = cyear - year;

    printf("Please enter the year you were born: \n");
    scanf("%i", &year);
    printf("Now enter the current year: \n");
    scanf("%i", &cyear);

    if (1 1 == 2){
        printf("You must be %i", age);
    }
    else {
        printf("Cannot compute age, GOODBYE:\n");
    }
    return 0;
}

CodePudding user response：

You are calculating the age before the input is taken from the user. So the age variable is storing a garbage value.

Solution:

Position the calculation of age after taking the input from user that is after taking input of cyear using scanf. The correct code is given below #include <stdio.h>

int main()
{
    int year;
    int cyear;
    int age =0;     //initialise with 0

    printf("Please enter the year you were born: \n");
    scanf("%i", &year);
    printf("Now enter the current year: \n");
    scanf("%i", &cyear);
    
    age = cyear - year;     //note the change here

    if (1 1 == 2){
        printf("You must be %i", age);
    }
    else {
        printf("Cannot compute age, GOODBYE:\n");
    }
    return 0;
}

CodePudding user response：

enter code here
   #include <stdio.h>
   int main()
   {
  long long int year;
  printf("Please enter the year you were born: \n");
scanf("%lld",&year);
long long int cyear;
  printf("Now enter the current year: \n");
scanf("%lld",&cyear);

long long  int age = cyear-year;

if (1){
    printf("You must be %lld", age);
}
else {  printf("Now enter the current year: \n");
scanf("%lld",&cyear);

    printf("Cannot compute age, GOODBYE:\n");
}
return 0;

}