Question

what the the work of fflush(stdin) in c programming.am bits confused coz my programming is working same with it or without...

Answer 1

when you program , good approach is to cover all the possible situation/condition your program may encounter.
in this case maybe you are lucky but suppose you make minor changes later on and then your program crashes , it`s bad.

P.S : actually you will not encounter any problem if you input string/char once.
E.g
gets(string_name) ; // this will work fine

//this will work for one iteration properly
while(some condition) {
gets(string_name);
}

Answer 2

i feel maybe i was not able to explain so clearly, maybe someone can come up with a better explanation

Answer 3

You \(\bf{NEVER}\) use fflush(stdin) in C. This is an undefined call and how it works can change from system to system.

http://faq.cprogramming.com/cgi-bin/smartfaq.cgi?answer=1052863818&id=1043284351

It is far better to find an alternate method that works on all compilers.

Answer 4

why ? its perfectly working in "c"...

Answer 5

Did you read the FAQ on it? On that compiler it is working... what about another one? What about if you start working for a company that wants standards based code? The standard says that is undefined, so you could lose a job for doing it.

Answer 6

oh yes,i did n thnks 4 ur help and sorry for stupid question...;)

Answer 7

The only stupid question is the one you do not ask! If you don't know, you need to find out. Now you are better prepared than any computer student that never learns this is an undefined and irregular performing function call.

Answer 8

hey, i got problem in declaring "456.3342520324414" this value which is given as a input by the user....thanks..advance..

Answer 9

What are you declaring it as?

Answer 10

i wanna declare it as "unsigned long long float/double" in c

Answer 11

Well, many of those are integer data types. I must be some sort of float to take in the decimals.
http://www.tutorialspoint.com/cprogramming/c_data_types.htm

Answer 12

So you need a long double or you need to do some other input handling. It might take a library if really long, accurate numbers are needed.

Answer 13

mine answer is giving me correct upto 4 decimal points bt what i wan is till 8 or 9 decimal point..

Answer 14

What you put up there is like 15 decimal places.

Answer 15

The Linux man (manual) pages are a great reference:

http://www.linuxmanpages.com/man3/fflush.3.php
subroutines:
http://www.linuxmanpages.com/man3/

top level:
http://www.linuxmanpages.com/

Answer 16

http://poj.org/problem?id=1001..this the problem am tailking about..

Answer 17

In that, the input is limited to 0.0 < R < 99.999. So do some tests on the input and if it is outside thar range, send an error to the user.

Answer 18

ya, i understood that,but the main problem is to store this value after "pow(r,n)",?

Answer 19

Well, pow works in doubles.

Answer 20

ya,power work in double bt the output doesnt give me the exact like in the example...

Answer 21

That sounds like an issue in formatting the output.

Answer 22

yes..it is..so got any idea...?

Answer 23

Have you looked up printf?
http://www.cplusplus.com/reference/cstdio/printf/

Look at g and G. That might help.

Answer 24

its not giving the right input...lol...lossing patients

Answer 25

Input or output? Also, floating point has rounding errors.... Can't remember if those are hard set or machine based.

Answer 26

so, how should it be corrected,could nt sleep 4 dis problem 4rm last night ...lol

Answer 27

Hmmm.... only thing I can think of would be to use the fixed comand, which will leave the 0s, then convert it to a string and parse the string to strip the 0s.

http://stackoverflow.com/questions/6010838/how-to-keep-doubles-from-converting-to-scientific-notation-when-using-and-string

That would make it with the 0s.

Answer 28

@Elkanah : for the fflush part
e.mccormick is right , try and avoid fflush because it`s compiler and OS dependent
from my personal experience it works perfectly in windows(gcc/codeblock) but doen`t work in linux(Ubuntu/gcc)

so i prefer to flush it myself
while((c = getchar()) != '\n'); because in many cases it`s '\n' that causes problems