How do I break loop in do while?

Question

How can I break the do while loop here in my code? The program should loop until the user inputs a valid year from the category.

When I enter the valid input, the printf still shows up even if it is meant to stop.

Here is the code below:

#include <stdio.h>
int main()
{
  float year;

  do {
    printf("Please input your year of birth :");
    scanf("%f", &year);

    if ((year >= 1946) && (year  <= 1964))
      printf("You belong to the baby boomer generation \n");
    else if ((year  >= 1965) && (year  <= 1980))
      printf("You belong to the Generation X \n");
    else if ((year  >= 1981) && (year  <= 1996))
      printf("You belong to the Millenials/Generation Y \n"); 
    else if ((year  >= 1997) && (year  <= 2012))
      printf("You belong to the Zoomers/Generation Z \n"); 
  } while(1946 > year < 2012);
}

I guess it was break in C lang. -> https://www.programiz.com/c-programming/c-break-continue-statement — Wortig, Feb 15 '22 at 12:20
`while(1946 > year < 2012);`. This does not do what you think it does. — William Pursell, Feb 15 '22 at 12:23
`float year;` How many decimals do you expect for a year? Why not make it an `int`? — Gerhardh, Feb 15 '22 at 14:41
@Airgelo, if your question has been answered, consider marking one as answer. — MOTIVECODEX, Feb 17 '22 at 08:16

dr_barto · Answer 1 · 2022-02-15T13:28:58.973

1

Your while condition does not work as you expect. For the computer, 1946 > year < 2012 is (1946 > year) < 2021; 1946 > year will be either 0 or 1, so in the end you have 0 < 2021 (or 1 < 2021), which is always true, and the loop won't stop.

Try to change it to e.g. 1946 > year && year < 2012.

See https://stackoverflow.com/a/6961728/5471218 for details.

edited Feb 15 '22 at 13:28

answered Feb 15 '22 at 12:25

dr_barto

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When `1946 > year` is true, you have `1 < 2021` which is also true. – William Pursell Feb 15 '22 at 12:28
@WilliamPursell true, that's why I wrote "will be 0 most of the time" ;) But good point, I'll update my answer to show that the comparison result is irrelevant. – dr_barto Feb 15 '22 at 13:26

score 1 · Answer 2 · answered Feb 15 '22 at 12:25

1

(1946 > year < 2012)

should be

(year > 1946 && year < 2012)

and break; should be used if you want to break it somewhere like

if(year == 2000)
break;

answered Feb 15 '22 at 12:25

MOTIVECODEX

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score 0 · Answer 3 · answered Feb 15 '22 at 12:46

Add an else condition to break the loop.

if ((year >= 1946) && (year  <= 1964))
  printf("You belong to the baby boomer generation \n");
else if ((year  >= 1965) && (year  <= 1980))
  printf("You belong to the Generation X \n");
else if ((year  >= 1981) && (year  <= 1996))
  printf("You belong to the Millenials/Generation Y \n"); 
else if ((year  >= 1997) && (year  <= 2012))
  printf("You belong to the Zoomers/Generation Z \n"); 
else
    break;

How do I break loop in do while?

3 Answers3