C Programming

General Questions

C Programming Exercise Mode

General Questions

Practice and master this topic with our carefully crafted questions.

10 Questions
15 Minutes
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Question 1
Which of the following statements should be used to obtain a remainder after dividing 3.14 by 2.1 ?

A
rem = 3.14 % 2.1;
B
rem = modf(3.14, 2.1);
C
rem = fmod(3.14, 2.1);
D
Remainder cannot be obtain in floating point division.
Correct Answer: Option C

fmod(x,y) - Calculates x modulo y, the remainder of x/y. 
This function is the same as the modulus operator. But fmod() performs floating point divisions.

Example:


#include <stdio.h>
#include <math.h>

int main ()
{
  printf ("fmod of 3.14/2.1 is %lf\n", fmod (3.14,2.1) );
  return 0;
}

Output:
fmod of 3.14/2.1 is 1.040000

Question 2
Is there any difference between following declarations? 

1 : extern int fun(); 
2 : int fun();

A
Both are identical
B
No difference, except extern int fun(); is probably in another file
C
int fun(); is overrided with extern int fun();
D
None of these
Correct Answer: Option B

extern int fun(); declaration in C is to indicate the existence of a global function and it is defined externally to the current module or in another file.

int fun(); declaration in C is to indicate the existence of a function inside the current module or in the same file.

Question 3
By default a real number is treated as a

A
float
B
double
C
long double
D
far double
Correct Answer: Option B

In computing, 'real number' often refers to non-complex floating-point numbers. It include both rational numbers, such as 42 and 3/4, and irrational numbers such as pi = 3.14159265...

When the accuracy of the floating point number is insufficient, we can use the double to define the number. The double is same as float but with longer precision and takes double space (8 bytes) than float.

To extend the precision further we can use long double which occupies 10 bytes of memory space.

Question 4

Which of the following is not user defined data type?

1 : 
struct book
{
    char name[10];
    float price;
    int pages;
};
2 : 
long int l = 2.35;
3 : 
enum day {Sun, Mon, Tue, Wed};

A
1
B
2
C
3
D
Both 1 and 2
Correct Answer: Option B

C data types classification are

1. Primary data types

     1. int

     2. char

     3. float

     4. double

     5. void

2. Secondary data types (or) User-defined data type

     1. Array

     2. Pointer

     3. Structure

     4. Union

     5. Enum

So, clearly long int l = 2.35; is not User-defined data type.
(i.e.long int l = 2.35; is the answer.)

Question 5
How would you round off a value from 1.66 to 2.0?

A
ceil(1.66)
B
floor(1.66)
C
roundup(1.66)
D
roundto(1.66)
Correct Answer: Option A 
/* Example for ceil() and floor() functions: */

#include<stdio.h>
#include<math.h>

int main()
{
    printf("\n Result : %f" , ceil(1.44) );
    printf("\n Result : %f" , ceil(1.66) );
 
    printf("\n Result : %f" , floor(1.44) );    
    printf("\n Result : %f" , floor(1.66) );

    return 0;
}
// Output:
// Result : 2.000000
// Result : 2.000000
// Result : 1.000000
// Result : 1.000000
Question 6
What are the types of linkages?

A
Internal and External
B
External, Internal and None
C
External and None
D
Internal
Correct Answer: Option B

External Linkage-> means global, non-static variables and functions.

Internal Linkage-> means static variables and functions with file scope.

None Linkage-> means Local variables.

Question 7
Which of the following special symbol allowed in a variable name?

A
* (asterisk)
B
| (pipeline)
C
- (hyphen)
D
_ (underscore)
Correct Answer: Option D

Variable names in C are made up of letters (upper and lower case) and digits. The underscore character ("_") is also permitted. Names must not begin with a digit.

Examples of valid (but not very descriptive) C variable names:

=> foo

=> Bar

=> BAZ

=> foo_bar

=> _foo42

=> _

=> QuUx

Question 8
When we mention the prototype of a function?

A
Defining
B
Declaring
C
Prototyping
D
Calling
Correct Answer: Option B

A function prototype in C or C++ is a declaration of a function that omits the function body but does specify the function's name, argument types and return type.

While a function definition specifies what a function does, a function prototype can be thought of as specifying its interface.

Question 9

In the following program where is the variable a getting defined and where it is getting declared?

#include<stdio.h>
int main()
{
    extern int a;
    printf("%d\n", a);
    return 0;
}
int a=20;

A
extern int a is declaration, int a = 20 is the definition
B
int a = 20 is declaration, extern int a is the definition
C
int a = 20 is definition, a is not defined
D
a is declared, a is not defined
Correct Answer: Option A

- During declaration we tell the datatype of the Variable.

- During definition the value is initialized.

Question 10
Identify which of the following are declarations 

1 : extern int x; 
2 : float square ( float x ) { ... } 
3 : double pow(double, double);

A
1
B
2
C
1 and 3
D
3
Correct Answer: Option C

extern int x; - is an external variable declaration.

double pow(double, double); - is a function prototype declaration.

Therefore, 1 and 3 are declarations. 2 is definition.