why does this program say 1700 is a leap year?

Code:

#include <stdio.h>
main()
{
      int year;
      printf("Enter a year\n");
      scanf("%d", &year);
      getchar();
      
      if (year%400==0)
      printf("%d = leap year", year);
                 else if((year%100==0)&&(year%400==0))
                 printf("%d = leap year", year);
                 else if(year%4==0)
                 printf("%d = leap year", year);
                 else
                 printf("%d = not a leap year", year);
      
      
      getchar();
      }

ok, so i've searched through prior threads about this topic, and i still have not been able to figure out an answer. thanks in advance for any help.

1700 is divisble by 4.
If you trace through the code manually or a debugger
you can easily figure that out.
Also please indent properly and main returns int.

Originally Posted by newbcore

Code:

                 else if(year%4==0)
                 printf("%d = leap year", year);

1700 is divisible by 4 if I'm not mistaken. That's why your code reports it as a leap year.

QuantumPete

You may want to try this:

Code:

$ cat isleap.c
#include <stdio.h>
#include <stdlib.h>

#define NUMYEARS 14

int main ()
{
 int year[NUMYEARS] = {1700, 1900, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008};
 int i;

 for (i = 0; i < NUMYEARS; i++) {
     if ( (year[i] % 4 == 0 && year[i] % 100 !=0) || (year[i] % 400 == 0) )  {
        printf("%d = leap year\n", year[i]);
     }
     else {
       printf("%d = not a leap year\n", year[i]);
     }
 }

 exit (0);
}

$ gcc -Wall isleap.c

$ a.out
1700 = not a leap year
1900 = not a leap year
1996 = leap year
1998 = not a leap year
1999 = not a leap year
2000 = leap year
2001 = not a leap year
2002 = not a leap year
2003 = not a leap year
2004 = leap year
2005 = not a leap year
2006 = not a leap year
2007 = not a leap year
2008 = leap year

Thanks for the help, y'all. Much appreciated!



Ok.

Originally Posted by stevesmithx

1700 is divisble by 4.
If you trace through the code manually or a debugger
you can easily figure that out.
Also please indent properly and main returns int.

I am certain you already know this, but I do feel compelled to mention it.

It's obvious that I couldn't figure it out. It's also obvious that I don't know what "indenting properly" actually is, or what "main returns int" means. I am trying to learn.

Do you think I'm trying to... I don't even know. Manipulate you? Don't feed me a line about laziness. What I posted above took me hours, however pathetic that may be to you.

Newbcore, we've all been there. Don't take any brusque replies personally. It's the nature of forums inability to "talk", at a decent speed, and very common on the internet.

Nobody's taking aim at you because you're a dumb programmer - because we were ALL dumb programmers, and some of us <clears throat> ain't too far from it, yet.

If you can get a "words roll off me like water off a duck's back", kind of attitude going, you'll learn a lot, a lot quicker. And don't worry, when the word's not rolling off your back, we got your back, OK?

What you may not know is all programmers have developed a visual acuity, just by programming so much, that indentation of another sort, just murders. You can go from running at top speed, scanning down a program's code, to feeling like you're running in quicksand. Uhh!

You'll get that way too, if you are actively programming, even as a hobby.

Thanks, Adak. I'll keep those comments in mind.

Originally Posted by newbcore

It's obvious that I couldn't figure it out. It's also obvious that I don't know what "indenting properly" actually is, or what "main returns int" means. I am trying to learn.

And that's why I was trying to help you.
The point of these forums is to not only to help you program but also to write good portable programs.
When I started to learn C by posting here at this forum I made these same mistakes and I was told to correct them by the experts here (in fact,a bit harshly sometimes)and I took their suggestions.
Indenting Properly
main returns int

If you are not sure about a term or jargon just google it and you'll usually get what you want.

Originally Posted by newbcore

Do you think I'm trying to... I don't even know. Manipulate you? Don't feed me a line about laziness. What I posted above took me hours, however pathetic that may be to you.

I never told that you were trying to.
I don't know about you ,but my laziness and mediocre typing speed doesn't permit me to write "No offence intended" at the end of every post I am replying to.
Finally, learn to have a thicker skin at the online forums because you are going to need it. [No offence intended]