Practical 3
Title: Create a C program to perform bitwise operations on integer variable and print the results.
In the arithmetic-logic unit (which is within the CPU), mathematical operations like:
addition, subtraction, multiplication and division are done in bit-level. To perform bit-
level operations in C programming, bitwise operators are used.
Operators Meaning of operators
& Bitwise AND
| Bitwise OR
^ Bitwise XOR
~ Bitwise complement
Shift left
>> Shift right
Bitwise AND Operator
The output of bitwise AND is 1 if the corresponding bits of two operands is 1. If
either bit of an operand is 0, the result of corresponding bit is evaluated to 0.
In C Programming, the bitwise AND operator is denoted by &.
Let us suppose the bitwise AND operation of two integers 12 and 25.
Let us suppose the bitwise AND operation of two integers 12 and 25.
12 = 00001100 (In Binary)
25 = 00011001 (In Binary)
Bit Operation of 12 and 25
00001100
& 00011001
________
00001000 = 8 (In decimal)
Bitwise OR Operator |
The output of bitwise OR is 1 if at least one corresponding bit of two operands is 1. In
C Programming, bitwise OR operator is denoted by |.
12 = 00001100 (In Binary)
25 = 00011001 (In Binary)
Bitwise OR Operation of 12 and 25
00001100
| 00011001
________
00011101 = 29 (In decimal)
Bitwise XOR (exclusive OR) Operator ^
The result of bitwise XOR operator is 1 if the corresponding bits of two operands are
opposite. It is denoted by ^.
12 = 00001100 (In Binary)
25 = 00011001 (In Binary)
Bitwise XOR Operation of 12 and 25
00001100
^ 00011001
________
00010101 = 21 (In decimal)
Bitwise Complement Operator ~
Bitwise complement operator is a unary operator (works on only one operand). It
changes 1 to 0 and 0 to 1. It is denoted by ~.
35 = 00100011 (In Binary)
Bitwise complement Operation of 35
~ 00100011
________
11011100 = 220 (In decimal)
Twist in Bitwise Complement Operator in C Programming
The bitwise complement of 35 (~35) is -36 instead of 220, but why?
For any integer n, bitwise complement of n will be -(n + 1). To understand this, you
should have the knowledge of 2's complement.
2's Complement
Two's complement is an operation on binary numbers. The 2's complement of a
number is equal to the complement of that number plus 1. For example:
Decimal Binary 2's complement
0 00000000 -(11111111+1) = -00000000 = -0(decimal)
1 00000001 -(11111110+1) = -11111111 = -256(decimal)
12 00001100 -(11110011+1) = -11110100 = -244(decimal)
220 11011100 -(00100011+1) = -00100100 = -36(decimal)
Note: Overflow is ignored while computing 2's complement.
The bitwise complement of 35 is 220 (in decimal). The 2's complement of 220 is -36.
Hence, the output is -36 instead of 220.
Bitwise Complement of Any Number N is -(N+1). Here's how:
bitwise complement of N = ~N (represented in 2's complement form)
2'complement of ~N= -(~(~N)+1) = -(N+1)
Shift Operators in C programming
There are two shift operators in C programming:
• Right shift operator
• Left shift operator.
Right Shift Operator
Right shift operator shifts all bits towards right by certain number of specified bits. It
is denoted by >>.
212 = 11010100 (In binary)
212 >> 2 = 00110101 (In binary) [Right shift by two bits]
212 >> 7 = 00000001 (In binary)
212 >> 8 = 00000000
212 >> 0 = 11010100 (No Shift)
Left Shift Operator
Left shift operator shifts all bits towards left by a certain number of specified bits. The
bit positions that have been vacated by the left shift operator are filled with 0. The
symbol of the left shift operator is <<.
212 = 11010100 (In binary)
212<<1 = 110101000 (In binary) [Left shift by one bit]
212<<0 = 11010100 (Shift by 0)
212<<4 = 110101000000 (In binary) =3392(In decimal)
