putchar() in C: Displaying One Character

putchar() writes one character to standard output. It is useful for character-by-character output, simple loops, filters and examples that pair naturally with getchar().

Syntax Top ↑

int result = putchar(character);

Print a Character and a Newline Top ↑

#include <stdio.h>

int main(void) {
    putchar('C');
    putchar('\n');

    return 0;
}

Read with getchar() and Write with putchar() Top ↑

#include <stdio.h>

int main(void) {
    int ch;

    printf("Enter one character: ");
    ch = getchar();

    if (ch != EOF) {
        putchar(ch);
        putchar('\n');
    }

    return 0;
}

Change the Letter Case Top ↑

#include <ctype.h>
#include <stdio.h>

int main(void) {
    int ch;

    printf("Enter a letter: ");
    ch = getchar();

    if (ch == EOF) {
        return 1;
    }

    if (islower((unsigned char)ch)) {
        putchar(toupper((unsigned char)ch));
    } else if (isupper((unsigned char)ch)) {
        putchar(tolower((unsigned char)ch));
    } else {
        putchar(ch);
    }

    putchar('\n');
    return 0;
}

The unsigned char cast is used before passing ordinary character values to the <ctype.h> functions.

Print a String Character by Character Top ↑

#include <stdio.h>

int main(void) {
    const char text[] = "plus2net";
    int i = 0;

    while (text[i] != '\0') {
        putchar(text[i]);
        i++;
    }

    putchar('\n');
    return 0;
}

Print A to Z Top ↑

#include <stdio.h>

int main(void) {
    for (int ch = 'A'; ch <= 'Z'; ch++) {
        putchar(ch);

        if (ch < 'Z') {
            putchar(' ');
        }
    }

    putchar('\n');
    return 0;
}

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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