Explain the Character operations in C language

Character operations in C language involve handling individual characters, which can be alphabetic (A-Z or a-z), numeric (0-9), whitespace, or special symbols. C provides various functions for character input, output, and manipulation.

Syntax

char variable_name = 'character';
char variable_name;

Character Declaration

Characters in C are declared using the char data type and can be initialized with character constants −

#include <stdio.h>

int main() {
    char a = 'A';        /* using character constant */
    char b = 65;         /* using ASCII value */
    char c;              /* declaration without initialization */
    
    printf("Character a: %c<br>", a);
    printf("Character b: %c<br>", b);
    printf("ASCII value of a: %d<br>", a);
    
    return 0;
}

Character a: A
Character b: A
ASCII value of a: 65

Character Input/Output Functions

C provides several functions for character input and output operations −

Example: Basic Character Input/Output

#include <stdio.h>

int main() {
    char ch;
    
    printf("Enter a character: ");
    scanf("%c", &ch);
    printf("You entered: %c<br>", ch);
    
    printf("Enter another character: ");
    ch = getchar();
    getchar(); /* consume newline */
    printf("Character using getchar(): ");
    putchar(ch);
    printf("<br>");
    
    return 0;
}

Enter a character: A
You entered: A
Enter another character: B
Character using getchar(): B

Example: Line Counting Program

The following program counts the number of lines in input using getchar() −

#include <stdio.h>

int main() {
    int count, num;
    printf("Enter multiple lines (Ctrl+D/Ctrl+Z to end):<br>");
    num = 0;
    while ((count = getchar()) != EOF) {
        if (count == '<br>') {
            ++num;
        }
    }
    printf("Number of lines: %d<br>", num);
    return 0;
}

Enter multiple lines (Ctrl+D/Ctrl+Z to end):
Hi
Hello
Welcome
^Z
Number of lines: 3

Key Points

• Characters are stored as ASCII values (0-127) in memory
• scanf("%c", &var) reads whitespace characters including newline
• getchar() reads one character at a time from standard input
• putchar() outputs a single character to standard output

Conclusion

Character operations in C provide fundamental building blocks for text processing. Understanding character input/output functions like getchar(), putchar(), and format specifiers enables efficient character manipulation in C programs.