ProgIntro

Operators

• An operator is a symbol that operates on one or more values or variables.
• e.g + is an operator which performs addition.
• C provides a wide range of operators for performing various tasks.

Arithmetic Operators

• arithmetic operators perform mathematical operations such as addition, subtraction, multiplication, division etc.

• Assume variables num1 holds the value 20 and num2 has holds the value 3
• Following table lists arithmetic operators, their description and sample usage:

Operator	Description	Example
+	Adds two operands.	A + B = 23
−	Subtracts second operand from the first.	A − B = 17
*	Multiplies both operands.	A * B = 60
/	Divides numerator by de-numerator.	A / B = 6
%	Modulus Operator and remainder of after an integer division.	A % B = 2

• changing the position of operands (i.e. A and B) may change the result in some cases
• e.g. A - B = 17 but B - A = -17similarly / and % will give different values when the position of A and B is changed.
• operators which operate on two operands are known as binary operators

link to c program on arithmetic operators

Arithmetic Assignment Operators

• C also provides arithmetic assignment operator which provide a concise way of writing expressions involving arithmetic and assignment.
• e.g. if a=4 then a = a + 2 (which means add 2 to a and assign the result to a) may be written as a+=2, note that a is not repeated.
• +=, -=, *=, /= and %= are all arithmetic assignment operators

link to c program on arithmetic assignment operators

Relational Operators

Operator	Description	Example
==	Checks if the values of two operands are equal or not. If yes, then the condition becomes true.	(A == B) is not true.
!=	Checks if the values of two operands are equal or not. If the values are not equal, then the condition becomes true.	(A != B) is true.
>	Checks if the value of left operand is greater than the value of right operand. If yes, then the condition becomes true.	(A > B) is not true.
<	Checks if the value of left operand is less than the value of right operand. If yes, then the condition becomes true.	(A < B) is true.
>=	Checks if the value of left operand is greater than or equal to the value of right operand. If yes, then the condition becomes true.	(A >= B) is not true.
<=	Checks if the value of left operand is less than or equal to the value of right operand. If yes, then the condition becomes true.	(A <= B) is true.

link to c program on relational operators

Logical Operators

Operator	Description	Example
&&	Called Logical AND operator. If both the operands are non-zero, then the condition becomes true.	(A && B) is false.
||	Called Logical OR Operator. If any of the two operands is non-zero, then the condition becomes true.	(A || B) is true.
!	Called Logical NOT Operator. It is used to reverse the logical state of its operand. If a condition is true, then Logical NOT operator will make it false.	!(A && B) is true.

Bitwise Operators

Bitwise operator works on bits and perform bit-by-bit operation. The truth tables for &, |, and ^ is as follows:

p	q	p & q	p | q	p ^ q
0	0	0	0	0
0	1	0	1	1
1	1	1	1	0
1	0	0	1	1

• Assume A = 60 and B = 13, their binary equivalent is A = 0011 1100, B = 0000 1101
• The following table lists the bitwise operators supported by C

Operator	Description	Example
&	Binary AND Operator copies a bit to the result if it exists in both operands.	(A & B) = 12, i.e., 0000 1100
|	Binary OR Operator copies a bit if it exists in either operand.	(A | B) = 61, i.e., 0011 1101
^	Binary XOR Operator copies the bit if it is set in one operand but not both.	(A ^ B) = 49, i.e., 0011 0001
~	Binary One’s Complement Operator is unary and has the effect of ‘flipping’ bits.	(~A ) = ~(60), i.e,. -0111101
«	Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.	A « 2 = 240 i.e., 1111 0000
»	Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand.	A » 2 = 15 i.e., 0000 1111