Learn C Programming Arithmetic Operator MCQ Questions and Answers on Basics to attend job placement exams, interview questions, college viva and Lab Tests

C language comes with Arithmetic Operators like Plus, Minus, Multiplication, Division and Modulo Division. One more operator ‘=’, also called Assignment operator is also present.

C Programming Arithmetic Operators are used to work with integers and real numbers.

Study C basics and keywords before this tutorial.

Arithmetic Operator

SNO	Operator	Description
1	+	Addition Operator
2	–	Subtraction Operator
3	*	Multiplication Operator
4	/	Multiplication Operator
5	%	Modulo Division Operator

C Programming Arithmetic Operator

Example 1:

int main()
{
  int a=5, b=10;
  int c;
  // = is Assignment operator
  c = a + b;
  printf("%d ", c);
  
  c = a - b;
  printf("%d ", c);
  
  c = a*b;
  printf("%d ", c);
  
  c = b/a;
  printf("%d ",c);

  c = a%b; //modulo division or remainder operator
  printf("%d", c);
  
  return 0;
}
//output:  15  -5  50  2  5

Assignment Operator allows only right side value to be assigned to the left side variable. In the above program, left side variable ‘C’ gets the value of right side operation like addition, subtraction etc.

Note: Modulo division operator works only with whole numbers like integers.

Note: Arithmetic operators can also be applied on char variables as characters are converted to their respective ASCII codes before arithmetic operation.

Integer and Float Conversions

When you are working with integers and float (Real) numbers, some number conversions are applied.

1. Result of int and int is integer only. Use %d format specifier. Use an int variable to hold data.
2. Result of float and float is float only. Use %f format specifier. Use a float variable to hold data.
3. Result of int and float is float only. Use %f format specifier. Use a float variable to hold data.
4. If you use %d instead of %f, precision data will be lost.
5. If you are working with long, double and long double data types, result of an arithmetic operation contains higher data type value. For example, arithmetic operation with short and int is always int.

Arithmetic Operator Example 1:

int main()
{
  int a=5, b=10;
  float c = 12.5f, d = 10.5f;
  
  //int + int
  printf("%d, ", a+b);
  
  //float + float
  printf("%f, ", c+d);
  
  //int + float
  printf("%f, ", a + c);
  
  //int + float
  printf("%d", a + c);
  //%d truncates extra data i.e precision
  
  return 0;
}
//output: 15, 23, 17.500000, 17

Example 2:

SNO	Arithmetic Operation	Result
1.	9/2	4
2.	9/2.0	4.5
3.	9.0/2	4.5
4.	9.0/2.0	4.5
5.	2/9	0
6.	2/9.0	0.22
7.	2.0/9	0.22
8.	2.0/9.0	0.22

Note: To avoid losing of precision data with division operator, multiply the numerator or denominator with 1.0f or 1.0 double value. Use parantheses ( ) operator to group all numerator or denominator expressions.

int main()
{
  int a=10, b=4;
  float c = (1.0f * a) / b;
  //multiply with 1.0f or 1.0
  printf("%f", c);
    
  return 0;
}
//output: 2.500000

C Operator Precedence or Priority or Hierarchy

Each operator in C has a precedence or priority or hierarchy. Operator precedence is useful to evaluate arithmetic expressions with operators of different priority. Operator priority decides which operator and operands should be evaluated first.

Note: Constants on the left and right side of operator are called Operands.

Example 1:

int main()
{
  int a=2, b=3, c=8;
  int d=0;
  d = a + b * c;
  printf("%d", d);
  
  return 9;
}
//output:
// 2 + (3*8)
// 2 + 24
// 26 is the output
//'*' operator has higher priority
// wrong = (a+b)*c

Arithmetic Operator Precedence Chart

Priority	Operator	Description
1st	*, /, %	Multiplication, Division, Modulo Division
2nd	+, –	Addition, Subtraction
3rd	=	Assignment

Example 2:

int main()
{
  float abc = 5 + 10 / 2 * 5 - 2 % 5;
  printf("Result=%f", abc);
  
  return 0;
}
//Evaluation steps
//10 / 2 * 5 left to right processing
//5 + 25 - 2 left to right processing
// START
// 5 + (10 / 2) * 5 - 2 % 5
// 5 + 5 * 5 - 2 % 5
// 5 + 25 - 2 % 5
// 5 + 25 - 2
// 30 - 2
// 28
//END

C Operator Associativity

C operator associativity deals with the problem of associating an operand to either left operator or right operator. When two equal priority operators are encountered in an expression, this Operator associativity is used to solve deadlock. Usually arithmetic operators follow Left to Right Associativity. Equals to ‘=’ operator follows Right to Left Associativity.

Example 1:

int d = 3 + 4 + 5;

Now as per Left to Associativity of arithmetic operators, 4 belongs to the left side + or first + operator. So the expression becomes (3+4) + 5. Next, the result of expression is added to 5 like (7)+5.

Now as per Right to Left Associativity of Equals to Operator, right side value is assigned to left side variable. So the variable d now holds a value of 12.

Example 2: 

float fd = 3 + 12 / 5;

In the code above, there are two operators + and /. As Division / operator has higher priority, operand 12 is associated with /.  instead of + on the left side. So 12/5 evaluates to 2. fd = 3 + 2 = 5 now.

learn C Programming Syntax Basics in this multipart tutorial which are useful for students in the last minute before exam. C Programming Language was invented by Dennis Ritchie in Bell Laboratories. Now Nokia owns Bell Laboratories and experiments are still going on.

C Programming Syntax Basics Part 1

We shall learn about basic structure of a C Program and predefined Keywords in this C Programming Syntax Basics Tutorial Part 1. You can set up a Turbo C Compiler on your Windows Machine easily.

Structure of a C Program

Every C program contains a function or method called main(). All functions end with Round Brackets or Paranthesis ( ). Inside Paratheses, arguments can be received or passed. Code of a Function is surrounded by Curly Brackets or Braces { }.

#include <stdio.h>
void main()
{
  /*This is a multi-line comment.
     It is not compiled or checked for Syntax*/
  printf("Hello C..");
}

Output

Hello C..

Observations

1. VOID is a return type. VOID means nothing is being returned.
2. main() { } is a compulsory function in any C Program.
3. void and main should be typed in lowercase completely.
4. / symbol is called Forward Slash or simply Slash.
5. * symbol is called STAR.
6. /* */ is a multiline comment. Comments are useful for analysing code logic flow in very big projects. Comments make others easily understand your program or project.
7. printf() is a function which is passing one argument “Helllo C”.
8. “Hello C” is a string literal here.
9. Code statements or lines end with Semicolon ;
10. Putting a return type before a function name is not mandatory in a C Compiler. If you use a C++ Compiler to compile c programs, you must specify a return type.
11. #include includes an already written header file stdio.h which contains code for printf function. Without predefined functions, life becomes difficult to write everything every time on our own. Also the code without including files becomes clumsy to maintain and understand.

Keywords in C Language

There are a total of 32 keywords in C Language which can not be used for the names of variables and functions. Find the C Programming Keyword list below. Students need to remember these keywords just like that to attempt questions asked in their exams.

Keyword	Meaning
auto	Defines local life time for a variable
break	Breaks a current loop in general
case	Defines branch control point
char	Basic data type, character literal
const	Defines a Constant, unmodified variable
continue	control goes to the loop beginning
default	control point used in switch construct in general
do	do while loop
double	Floating point data type bigger than float type
else	Usually followed by if construct. If conditon fails, branch to else block
enum	Used to define a  group of int constants like array
extern	Used to define a variable or function with type and the definition may exist some where
float	Floating point data type
for	For Loop
goto	Transfers execution control to defined Label
if	A conditional statement
int	Basic integer data type
long	Integer data type bigger than int
register	Tells to store the variable in RAM register
return	ends execution immediately
short	Type Modifier
signed	Type Modifier
sizeof	used to get the size of a variable. Eg. sizeof(integerType)
static	used to create a variable with broad scope
struct	Used to define a custom data type kind of thing
switch	switch branch control
typedef	used to create new type
union	used in grouping of variables of same type
unsigned	Modifiere used to increase positive max value
void	empty data type or return type
volatile	Used to create a variable with a value changed by any external process
while	while loop with a condition

[WpProQuiz 25]

Arithmetic Operator interview MCQ

1) What is the Priority among (*, /, %), (+, -) and (=) C Operators.?

A) (*, /, %) >  (+, -) < (=)

B) (*, /, %) <  (+, -) < (=)

C) (*, /, %) >  (+, -) > (=)

D) (*, /, %) <  (+, -) (+, -) == (=)

Answer [=] C

Explanation:

Assignment operator in C has the least priority.

2) What is the output of the C statement.?

int main()
{
    int a=0;
    a = 4 + 4/2*5 + 20;
    printf("%d", a);

    return 0;
}

A) 40

B) 4

C) 34

D) 54

Answer [=] C

Explanation:

/ and * has equal priority. But associativity is from L to R.

4 + 2*5 + 20

4 + 10 + 20 = 34

3) What is the output of the C Program.?

int main()
{
    int a=0;
    a = 10 + 5 * 2 * 8 / 2 + 4;
    printf("%d", a);

    return 0;
}

A) 124

B) 54

C) 23

D) 404

Answer [=] B

Explanation:

10 + 10*8/2 + 4

And 10 + 80/2 + 4

10 + 40 + 4 = 54

4) What is the output of the C Program.?

int main()
{
    int a=0;
    a = 4 + 5/2*10 + 5;
    printf("%d", a);

    return 0;
}

A) 29

B) 5

C) 4

D) 34

Answer [=] A

Explanation:

5/2 is 2 only because both numerator and denominator are integers. So only int value i.e 2 is the result.

4 + 2 * 10 + 5

4 + 20 + 5 = 29.

5) What is the output of the C Program.?

int main()
{
    int a=0;
    a = 10 + 2 * 12 /(3*2) + 5;
    printf("%d", a);

    return 0;
}

A) 31

B) 19

C) 11

D) 29

Answer [=] B

Explanation:

Paranthesis changes the associativity of operators.

10 + 2 * 12 / (3*2) + 5;

And 10 + 24 / (3*2) + 5;

10+ 24/6 + 5;

10 + 4 + 5 = 19;

6) What is the output of the C Program.?

int main()
{
    int a=0;
    a = 10 + 2 * 12 / 3 * 2 + 5;
    printf("%d", a);

    return 0;
}

A) 19

B) 31

C) 11

D) 25

Answer [=] B

Explanation:

10 + 2 * 12 / 3 * 2 + 5;

And 10 + 24/3*2 + 5;

10 + 8*2 + 5;

10 + 16 + 5 = 31;

7) What is the output of the C Program.?

int main()
{
    float a=10.0;
    a = a % 3;
    printf("%f", a);

    return 0;
}

A) 0

B) 1

C) 1.000000

D) Compiler error.

Answer [=] D

Explanation:

You can use the operator Modulus Division % with only integers.

 error: invalid operands to binary % (have ‘float’ and ‘int’)
     a = a % 3;
           ^

8) What is the output of the C Program.?

int main()
{
    float a=10.0;
    a = (int)a % 3;
    printf("%f", a);

    return 0;
}

A) 0

B) 1

C) 1.000000

D) Compiler Error.

Answer [=] C

Explanation:

Type casting from float to int is done by (int).

(int)10.000000  = 10;

10%3 = 1. Reminder of the division of 10 by 3.

%f in printf prints it as 1.000000.

9) What is the output of the C Program.?

int main()
{
    int a=0;
    a = 14%-5 - 2;
    printf("%d", a);

    return 0;
}

A) 0

B) -4

C) -2

D) 2

Answer [=] D

Explanation:

14%5  = 4 ( Reminder)

14 % -5  = 4. Yes sign of the reminder is the sign of Numerator.

4- 2 = 2;

10) What is the output of the C Program.?

int main()
{
    int a= 3 + 5/2;
    printf("%d", a);

    return 0;
}

A) 3

B) 2

C) 5

D) Can not assign an expression to variable at the time of declaration.

Answer [=] C

Explanation:

Assignment Operator = in C language has the least priority. So the right hand side expression is evaluated first and then assigned to the left side variable.

a = 3 + 5/2;

And a = 3 + 2;

a = 5;