Complete ASCII Table — Character Codes Reference

#include <stdio.h>

int main() {
    printf("Dec  Hex  Oct  Char  Description\n");
    printf("---  ---  ---  ----  -----------\n");

    for (int i = 32; i <= 126; i++) {
        printf("%-4d %-4X %-4o %-5c Printable\n", i, i, i, i);
    }

    // Character to ASCII
    char ch = 'A';
    printf("\n'%c' = ASCII %d (Hex: %X)\n", ch, ch, ch);

    // ASCII to character
    int code = 97;
    printf("ASCII %d = '%c'\n", code, code);

    return 0;
}

// Character → ASCII code
console.log("'A' →", "A".charCodeAt(0));   // 65
console.log("'a' →", "a".charCodeAt(0));   // 97
console.log("'0' →", "0".charCodeAt(0));   // 48
console.log("'!' →", "!".charCodeAt(0));   // 33

// ASCII code → Character
console.log("65 →", String.fromCharCode(65));   // A
console.log("97 →", String.fromCharCode(97));   // a
console.log("48 →", String.fromCharCode(48));   // 0

// Print all printable ASCII characters
let table = "";
for (let i = 32; i <= 126; i++) {
    table += String.fromCharCode(i) + " ";
    if ((i - 31) % 16 === 0) table += "\n";
}
console.log("\nPrintable ASCII:\n" + table);

// Check if character is uppercase
const isUpper = (ch) => {
    const code = ch.charCodeAt(0);
    return code >= 65 && code <= 90;
};
console.log("\nIs 'H' uppercase?", isUpper("H")); // true
console.log("Is 'h' uppercase?", isUpper("h"));    // false

// Convert lowercase to uppercase using ASCII
const toUpper = (ch) =>
    String.fromCharCode(ch.charCodeAt(0) - 32);
console.log("'d' to upper:", toUpper("d")); // D

# Character → ASCII code
print("'A' →", ord('A'))    # 65
print("'a' →", ord('a'))    # 97
print("'0' →", ord('0'))    # 48

# ASCII code → Character
print("65 →", chr(65))      # A
print("97 →", chr(97))      # a

# Print printable ASCII table
print("\nPrintable ASCII Characters:")
for i in range(32, 127):
    print(f"{i:3d} {i:02X} {chr(i):>3}", end="  ")
    if (i - 31) % 8 == 0:
        print()

# Uppercase check
def is_upper(ch):
    return 65 <= ord(ch) <= 90

print(f"\nIs 'H' upper? {is_upper('H')}")

# Caesar cipher (rotate by 3)
def caesar_encrypt(text, shift=3):
    result = ""
    for ch in text:
        if ch.isalpha():
            base = ord('A') if ch.isupper() else ord('a')
            result += chr((ord(ch) - base + shift) % 26 + base)
        else:
            result += ch
    return result

msg = "Hello India"
encrypted = caesar_encrypt(msg)
print(f"\nOriginal:  {msg}")
print(f"Encrypted: {encrypted}")
print(f"Decrypted: {caesar_encrypt(encrypted, -3)}")