Here is a listing of C interview questions on “Character Class Testing & Conversions” along with answers, explanations and/or solutions:
1. Which is true about isaplpha(c), where c is an int that can be represented as an unsigned?
char or EOF.isalpha(c) returns
a) Non-zero if c is alphabetic
b) 0 if c is not alphabetic
c) Both Non-zero if c is alphabetic & 0 if c is not alphabetic
d) None of the mentioned
View Answer
Explanation: None.
2. Which is true about isupper(c), where c is an int that can be represented as an unsigned?
char or EOF.isupper(c) returns
a) Non-zero if c is upper case
b) 0 if c is not upper case
c) Nothing
d) Both Non-zero if c is upper case & 0 if c is not upper case
View Answer
Explanation: None.
3. Which is true about isalnum(c), where c is an int that can be represented as an unsigned?
char or EOF.isalnum(c) returns
a) Non-zero if isalpha(c) or isdigit(c)
b) 0 if not isalpha(c) or not isdigit(c)
c) Both Non-zero if isalpha(c) or isdigit(c) & 0 if not isalpha(c) or not isdigit(c)
d) None of the mentioned
View Answer
Explanation: None.
4. What will be the output of the following C code?
#include <stdio.h>#include <ctype.h>int main()
{char c = 't';
printf("%d\n", isspace(c));
}
a) Non-zero number
b) Nothing
c) Error
d) t
View Answer
Explanation: None.
5. What will be the output of the following C code?
#include <stdio.h>#include <ctype.h>int main()
{char c = 't';
printf("is :%c\n", tolower('A'));
}
a) A
b) a
c) Non-zero number
d) Zero
View Answer
Explanation: None.
6. Which types of input are accepted in toupper(c)?
a) char
b) char *
c) float
d) Both char and char *
View Answer
Explanation: None.
7. What is the difference in the ASCII value of capital and non-capital of the same letter is?
a) 1
b) 16
c) 32
d) Depends with compiler
View Answer
Explanation: None.
Sanfoundry Global Education & Learning Series – C Programming Language.
