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.

Solution 1

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.

Solution 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

Comments

[anuj pradhan]

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.

[anuj pradhan]

still the same problem.

[Yu Hao]

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