# Write short notes on: History of C Bitwise Operator

### a) History of C

C programming language was developed in 1972 by Dennis Ritchie at bell laboratories of AT&T (American Telephone & Telegraph), located in the U.S.A.

Dennis Ritchie is known as the founder of the c language.

It was developed to overcome the problems of previous languages such as B, BCPL, etc.

Initially, C language was developed to be used in UNIX operating system. It inherits many features of previous languages such as B and BCPL.

Let’s see the programming languages that were developed before C language.

Language Year Developed By
Algol 1960 International Group
BCPL 1967 Martin Richard
B 1970 Ken Thompson
K & R C 1978 Kernighan & Dennis Ritchie
ANSI C 1989 ANSI Committee
ANSI/ISO C 1990 ISO Committee
C99 1999 Standardization Committee

### b) Bitwise operator:

The following table lists the Bitwise operators supported by C. Assume variable ‘A’ holds 60 and variable ‘B’ holds 13, then −

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,. 1100 0011
<< 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

Example

Try the following example to understand all the bitwise operators available in C −

#include <stdio.h>

main() {

unsigned int a = 60;	/* 60 = 0011 1100 */
unsigned int b = 13;	/* 13 = 0000 1101 */
int c = 0;

c = a & b;       /* 12 = 0000 1100 */
printf("Line 1 - Value of c is %d\n", c );

c = a | b;       /* 61 = 0011 1101 */
printf("Line 2 - Value of c is %d\n", c );

c = a ^ b;       /* 49 = 0011 0001 */
printf("Line 3 - Value of c is %d\n", c );

c = ~a;          /*-61 = 1100 0011 */
printf("Line 4 - Value of c is %d\n", c );

c = a << 2;     /* 240 = 1111 0000 */
printf("Line 5 - Value of c is %d\n", c );

c = a >> 2;     /* 15 = 0000 1111 */
printf("Line 6 - Value of c is %d\n", c );
}

The output of above program is

Line 1 - Value of c is 12
Line 2 - Value of c is 61
Line 3 - Value of c is 49
Line 4 - Value of c is -61
Line 5 - Value of c is 240
Line 6 - Value of c is 15