Arithmetic Operators in C

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Arithmetic operators in C are certain special symbols, predefined to perform arithmetic operations. We are familiar with the basic arithmetic operations − addition, subtraction, multiplication and division. C is a computational language, so these operators are essential in performing a computerised process.

In addition to the above operations assigned to the four symbols +, −, *, and / respectively, C has another arithmetic operator called the modulo operator for which we use the %symbol.

The following table lists the arithmetic operators in C −

The ++ and -- operators are also listed in the above table. We shall learn about increment and decrement operators in a separate chapter.

Example: Arithmetic Operators in C

The following example demonstrates how to use these arithmetic operators in a C program −

#include <stdio.h>

int main(){

   int op1 = 10;
   int op2 = 3;

   printf("Operand1: %d Operand2: %d \n\n", op1, op2);  
   printf("Addition of op1 and op2: %d\n", op1 + op2);
   printf("Subtraction of op2 from op1: %d\n", op1 - op2);
   printf("Multiplication of op1 and op2: %d\n", op1 * op2);
   printf("Division of op1 by op2: %d\n", op1/op2);

   return 0;
}

Output

When you run this code, it will produce the following output −

Operand1: 10 Operand2: 3

Addition of op1 and op2: 13
Subtraction of op2 from op1: 7
Multiplication of op1 and op2: 30
Division of op1 by op2: 3

Type Casting in C

The first three results are as expected, but the result of division is not. You expect 10/3 to be a fractional number (3.333333). Is it because we used the %d format specifier to print the outcome of the division? If we change the last line of the code as follows −

printf("Division of op1 by op2: %f\n", op1/op2);

Now the outcome of the division operation will be "0.000000", which is even more surprising. The reason why C behaves like this is because the division of an integer with another integer always returns an integer.

To obtain floating-point division, at least one operand must be a float, or you need to use the typecast operator to change one of the integer operands to float.

Now, change the last printf statement of the given program as follows −

printf("Division of op1 by op2: %f\n", (float)op1/op2);

When you run run the code again after making this change, it will show the correct division −

Division of op1 by op2: 3.333333

Note: If you use %d format specifier for a floating-point expression, it will always result in "0".

Example

The result of arithmetic operations with at least one float (or double) operand is always float. Take a look at the following example −

#include <stdio.h>

int main(){

   int op1 = 10;
   float op2 = 2.5;

   printf("Operand1: %d Operand2: %f\n", op1, op2);
   printf("Addition of op1 and op2: %f\n", op1 + op2);
   printf("Subtraction of op2 from op1: %f\n", op1 - op2);
   printf("Multiplication of op1 and op2: %f\n", op1 * op2);
   printf("Division of op1 by op2: %f\n", op1/op2);

   return 0;
}

Output

Run the code and check its output −

Operand1: 10 Operand2: 2.500000
Addition of op1 and op2: 12.500000
Subtraction of op2 from op1: 7.500000
Multiplication of op1 and op2: 25.000000
Division of op1 by op2: 4.000000

Arithmetic Operations with char Data Type

In C, char data type is a subset of int type. Hence, we can perform arithmetic operations with char operands.

Example

The following example shows how you can perform arithmetic operations with two operands out of which one is a "char" type −

#include <stdio.h>

int main(){

   char op1 = 'F';
   int op2 = 3;

   printf("operand1: %c operand2: %d\n", op1, op2);
   printf("Addition of op1 and op2: %d\n", op1 + op2);
   printf("Subtraction of op2 from op1: %d\n", op1 - op2);
   printf("Multiplication of op1 and op2: %d\n", op1 * op2);
   printf("Division of op1 by op2: %d\n", op1/op2);

   return 0;
}

Output

Run the code and check its output −

operand1: F operand2: 3

Addition of op1 and op2: 73
Subtraction of op2 from op1: 67
Multiplication of op1 and op2: 210
Division of op1 by op2: 23

Since a char data type is a subset of int, the %c format specifier returns the ASCII character associated with an integer returned by the %d specifier.

If any arithmetic operation between two char operands results in an integer beyond the range of char, the %c specifier displays blank.

Modulo Operator in C

The modulo operator (%) returns the remainder of a division operation.

Example

Take a look at the following example −

#include <stdio.h>

int main(){

   int op1 = 10;
   int op2 = 3;

   printf("Operand1: %d Operand2: %d\n", op1, op2);
   printf("Modulo of op1 and op2: %d\n", op1%op2);

   return 0;
}

Output

Run the code and check its output −

Operand1: 10 Operand2: 3
Modulo of op1 and op2: 1

The modulo operator needs both the operands of int type. If not, the compiler gives a type mismatch error. For example, change the data type of "op1" to float in the above code and run the program again −

float op1 = 10;
int op2 = 3;
printf("Modulo of op1 and op2: %d\n", op1%op2);

Now, you will get a type mismatch error with the following message −

error: invalid operands to binary % (have 'float' and 'int')

It does allow char operands for modulo operations though.

Negation Operator in C

The increment and decrement operators represented by the symbols ++ and -- are unary operators. They have been covered in a separate chapter. The "−" symbol, representing subtraction operator, also acts a unary negation operator.

Example

The following example highlights how you can use the negation operator in C −

#include <stdio.h>

int main(){

   int op1 = 5;
   int op2 = -op1;

   printf("Operand1: %d Operand2: %d\n", op1, op2);

   return 0;
}

Output

When you run this code, it will produce the following output −

Operand1: 5 Operand2: -5

In the above example, the "–" symbol returns the negative value of op1 and assigns the same to op2.