Character Class Testing & Conversions Quiz Online Practice Test

1. Which of the following library functions performs operations in a case-sensitive manner?

toupper()

tolower()

isdigit()

All of these

2. Which of the following C expressions is equivalent to the given condition?
if (isalpha(c) && isdigit(c))

if (isalnum(c))

if (isalphanum(c))

if (isalphanumeric(c))

None of these

3. Which of the following will produce a non-zero result when evaluated with isspace(c)?

Blank space

Newline

Return

All of these

4. What will the following C code display upon execution?
#include <stdio.h>
#include <ctype.h>
int main()
{
char i = 9;
if (isdigit(i))
printf("digit\n");
else
printf("not digit\n");
return 0;
}

It will print "digit"

It will print "not digit"

The output varies by compiler

None of the options are correct

5. What output will the following C program produce when executed?
#include <stdio.h>
#include <ctype.h>
int main()
{
int i = 9;
if (isdigit(i))
printf("digit\n");
else
printf("not digit\n");
return 0;
}

It will output "digit"

It will output "not digit"

The output is compiler-dependent

None of these

6. What will be the result of executing the following C code?
#include <stdio.h>
int main()
{
char i = '9';
if (isdigit(i))
printf("digit\n");
else
printf("not digit\n");
return 0;
}

It will print "digit"

It will print "not digit"

The result varies by compiler

None of these

7. What output will the following C program generate upon execution?
#include <stdio.h>
#include <ctype.h>
int main()
{
int i = 0;
if (isspace(i))
printf("space\n");
else
printf("not space\n");
return 0;
}

Compile-time error

It will print "space"

It will print "not space"

None of the options apply

8. What will the output be when the following C program is executed?
#include <stdio.h>
#include <ctype.h>
int main()
{
int i = 32;
if (isspace(i))
printf("space\n");
else
printf("not space\n");
return 0;
}

Compile-time error

It will print "space"

It will print "not space"

None of these

9. Which statement is correct regarding isalpha(c), where c is an int that can be represented as an unsigned char or EOF?

Returns a non-zero value if c is an alphabetic character

Returns 0 if c is not an alphabetic character

Both returns a non-zero value if c is alphabetic and 0 if c is not

None of the above

10. What is true about isupper(c), where c is an int that can be represented as an unsigned char or EOF?

It returns a non-zero value if c is an uppercase letter

It returns 0 if c is not an uppercase letter

It returns nothing

It returns both a non-zero value if c is uppercase and 0 if c is not

11. Which statement accurately describes isalnum(c), where c is an int that can be represented as an unsigned char or EOF?

It returns a non-zero value if isalpha(c) or isdigit(c) is true

It returns 0 if c is neither an alphabetic nor a digit character

It returns both a non-zero value if isalpha(c) or isdigit(c) is true, and 0 if neither is true

None of the above

12. What will be the output of the following C program when executed?
#include <stdio.h>
#include <ctype.h>
int main()
{
char c = 't';
printf("%d\n", isspace(c));
}

A non-zero number

No output

Compilation error

The character 't'

13. What will be the output of the following C program upon execution?
#include <stdio.h>
#include <ctype.h>
int main()
{
char c = 't';
printf("is :%c\n", tolower('A'));
}

A non-zero number

Zero

14. What types of input can be accepted by the toupper(c) function?

char

char *

float

Both char and char *

15. What is the ASCII value difference between an uppercase letter and its corresponding lowercase letter?

It varies with the compiler

Test Name:	Character Class Testing & Conversions Quiz
Subject Category:	C Programming
Test Type:	Multiple Choice Questions
Total Score / Questions:	15 / 15
Time Allowed:	10 Min
Who Should Practice this Test:	Students, job seekers, or professionals preparing for competitive exams and interviews.

Character Class Testing & Conversions MCQ Quiz Online Practice Test