multiple character input to char in C

Question

#include <stdio.h>

int main(void) {
   char ch,ch1;
   scanf("%c",&ch);/*input ab here*/
   scanf("%c",&ch1);
   printf("%c %c",ch,ch1);
   return 0;
}

Why this produces a b as output. We don't enter any input for second variable but it still got assigned. Could anyone explain the behavior.

You can check the output here if you want.

"%c" scans one byte of input, which consumes a, and b is still in the input stream when the second scanf() gets called. That's just how scanf() works. — jxh
– jxh, Commented Jul 17, 2014 at 7:22
You don't handle the newline, %c doesn't skip blank lines. — Maroun
– Maroun, Commented Jul 17, 2014 at 7:23
Are you trying to put multiple characters in a char? That's what the question title looks like. I haven't messed around with <stdio.h> because I use C++ and <iostream>, but %c looks like, at a glance, the syntax to represent a char in <stdio.h>. Correct me if I'm wrong, please. :) — Tqn
– Tqn, Commented Jul 17, 2014 at 7:31

Yu Hao · Accepted Answer · 2014-07-17 07:23:52Z

2

We don't enter any input for second variable

That's not true, "%c" in scanf reads one character, after it processes the input a, the "%c" in the next scanf then reads the next input character b.

answered Jul 17, 2014 at 7:23

Yu Hao

123k50 gold badges253 silver badges305 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

anuj pradhan Over a year ago

But dont you think scanf ends the input after encountering a newline character. Here We enter the new line character after typing 'ab'. Then how come b goes to second variable.

Yu Hao Over a year ago

@anujpradhan Add another scanf("%c",&ch2); after the second, you'll see the newline character in ch2.

n0p · Accepted Answer · 2014-07-17 07:24:08Z

2

Because you entered 2 characters in the 1st input while the program expects just 1: the 2nd is pending until the next call to scanf

answered Jul 17, 2014 at 7:24

n0p

3,5062 gold badges32 silver badges53 bronze badges

Comments

chouaib · Accepted Answer · 2014-07-17 08:23:34Z

0

this may get you rid of the situation

scanf("%c",&ch);/*input ab here*/
fflush(stdin);
scanf("%c",&ch1);

EDIT Your actual problem is that ch1 is being assigned with the newline character(or the space as tried in IDEONE simulator)

To check that : enter your values without any separation.

edited Jul 17, 2014 at 8:23

answered Jul 17, 2014 at 7:33

chouaib

2,8175 gold badges23 silver badges36 bronze badges

1 Comment

anuj pradhan Over a year ago

still the same problem.

Kaue Aftimus · Accepted Answer · 2016-02-26 02:06:40Z

0

Scanf can do multiple scans:

char a1, a2, a3, a4;
scanf("%c%c%c%c", &a1, &a2, &a3, &a4);

answered Feb 26, 2016 at 2:06

Kaue Aftimus

212 bronze badges

Collectives™ on Stack Overflow

multiple character input to char in C

4 Answers 4

2 Comments

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related