issue with switch statement c language - c

Question

So this is the code I'm working on. All is good except that I need to match the case with the counter so I can manage to display the desired output "you are in your tens / teens". I tried many different approaches but I couldn't get it right. However, I think the problem is within the condition. Any tips? Note: I'm just a beginner who just started programming in C this semester!
#include <stdio.h>
int main()
{
int YoB, CY, Age;
unsigned int counter = 0;
printf("Please enter your year of birth");
scanf_s("%d", &YoB);
printf("Please enter the current year");
scanf_s("%d", &CY);
Age = CY - YoB;
printf("Entered year of birth %d\n", YoB);
printf("Entered current year %d\n", CY);
printf("You are %d years old\n \n", Age);
if (Age > 18) {
puts("You are an adult\n");
if (Age < 18)
puts("You are a minor\n");
}
if(Age<=100){
while (++counter <= 10);
}
switch (counter) {
case 0:
puts("You are less than 10\n");
break;
case 1:
puts("you are in your tens / teens\n");
break;
case 2:
puts("You are in your twenties\n");
break;
case 3:
puts("You are in your thirties\n");
break;
case 4:
puts("You are in your fourties\n");
break;
case 5:
puts("You are in your fifties\n");
break;
case 6:
puts("You are in your sixties\n");
break;
case 7:
puts("You are in your seventies\n");
break;
case 8:
puts("You are in your eighties\n");
break;
case 9:
puts("You are in your nineties\n");
break;
case 10:
puts("You are a 100+!!\n");
break;
default:
puts("invalid age!");
break;
}
return 0;
}

Answer 1

Answer to your problem
You have a simple logic issue in your "counter-setter-loop" (I don't know how I should call this).
if(Age<=100){
while (++counter <= 10);
}
you're incrementing counter to 11 not 10. Suppose counter is 10, it'll iterate again, since the condition <= 10 is still true. As a result you'd need to change this part to:
if(Age<=100){
while (++counter < 10);
}
Code review
Anyway, when I saw your code, some code improvements went through my head. I hope that's fine for you, if not, you can skip this.
adding \n to printf (little UI improvement)
In my opinion it looks a little bit better, if you create a little prompt and create a new line for the input:
printf("Please enter your year of birth\n>> ");
scanf_s("%d", &YoB);
printf("Please enter the current year\n>> ");
scanf_s("%d", &CY);
Logic issue:
There's a logic issue in this part:
if (Age > 18) {
puts("You are an adult\n");
if (Age < 18)
puts("You are a minor\n");
}
Assuming Age is < 18. I think that you'd expect to have the output You are a minor. But this will never happen because in order to get to the if (Age < 18) condition, you'd need to enter the Age > 18 condition. So I think you mean it like that:
// Also keep in mind that Age can be "< 0" if the user used a "bad" input.
if (Age < 0) {
puts("You are not born yet.");
} else if (Age >= 18) {
puts("You are an adult\n");
} else {
puts("You are a minor\n");
}
Set counter a value instead of using a loop
You can change this part:
if (Age <= 100){
while (++counter <= 10);
}
to this:
if (Age <= 100) {
counter = 10;
}
although I don't really understand how you can enter the other case-arms since counter seems to be only 0 or 10 due to the condition above. I think you rather mean something like this:
if (Age <= 100) {
counter = Age / 10;
}
Also please use variable-names which start with a lowercase and not with a uppercase since uppercase Names are rather used for structs, enums or constants etc.
To sum it up, I'd do it as follows:
#include <stdio.h>
int main()
{
int birth_year, current_year, age;
unsigned int tenths = 0;
printf("Please enter your year of birth\n>> ");
scanf_s("%d", &birth_year);
printf("Please enter the current year\n>> ");
scanf_s("%d", &current_year);
age = current_year - birth_year;
printf("Entered year of birth %d\n", birth_year);
printf("Entered current year %d\n", current_year);
printf("You are %d years old\n \n", age);
if (age < 0) {
puts("You aren't born yet.");
} else if (age >= 18) {
puts("You are an adult.\n");
} else {
puts("You are a minor.\n");
}
if(age <= 100){
tenths = age % 10;
}
switch (tenths) {
case 0:
puts("You are less than 10\n");
break;
case 1:
puts("you are in your tens / teens\n");
break;
case 2:
puts("You are in your twenties\n");
break;
case 3:
puts("You are in your thirties\n");
break;
case 4:
puts("You are in your fourties\n");
break;
case 5:
puts("You are in your fifties\n");
break;
case 6:
puts("You are in your sixties\n");
break;
case 7:
puts("You are in your seventies\n");
break;
case 8:
puts("You are in your eighties\n");
break;
case 9:
puts("You are in your nineties\n");
break;
case 10:
puts("You are a 100+!!\n");
break;
default:
puts("invalid age!");
break;
}
return 0;
}