Here is a listing of C programming interview questions on “Ungetc Function” along with answers, explanations and/or solutions:
1. ungetc() can be used only with getc().
a) true
b) false
c) depends on the standard
d) depends on the platform
View Answer
Explanation: None.
2. Which character of pushback is guaranteed per file?
a) True
b) False
c) Depends on the compiler
d) Depends on the platform
View Answer
Explanation: None.
3. What is the output of this C code?
#include <stdio.h>int main()
{int n;
scanf("%d", &n);
ungetc(n, stdin);
scanf("%d", &n);
printf("%d\n", n);
return 0;
}
a) Compile time error
b) Whatever is typed by the user first time
c) Whatever is typed by the user second time
d) Undefined behaviour
View Answer
Explanation: None.
4. What is the output of this C code?
#include <stdio.h>int main()
{char n[20];
fgets(n, 19, stdin);
ungetc(n[0], stdin);
scanf("%s", n);
printf("%s\n", n);
return 0;
}
a) Compile time error
b) Whatever string user types second time
c) Whatever string user types first time
d) first character of whatever user types first time and whatever user types second time
View Answer
Explanation: None.
5. What is the output of this code considering user typed jkl?
#include <stdio.h>int main()
{char n[20];
fgets(n, 19, stdin);
ungetc(n[0], stdin);
printf("%s\n", n);
return 0;
}
a) jkl
b) kl
c) Undefined behaviour
d) jk
View Answer
Explanation: None.
6. How many characters for pushback is guaranteed per file while using
ungetc(c, fp);
a) Only 1 character
b) Characters within 1 word
c) Characters within 1st new-line
d) All characters upto NULL character
View Answer
Explanation: None.
7. Which of the following is the correct syntax for calling function ungetc()?
Assume int c and FILE *fp
a) ungetc(c,*fp);
b) ungetc(c, fp);
c) ungetc(fp, c);
d) ungetc(*fp,c);
View Answer
Explanation: None.
8. ungetc() is used
a) to get a char
b) to get an int
c) to push a character back to file
d) nothing
View Answer
Explanation: None.
Sanfoundry Global Education & Learning Series – C Programming Language.
