The char Data Type in C++

In C++, the char data type is used to store single characters. It stands for character and occupies 1 byte (8 bits) of memory. The char type is fundamental for handling textual data, working with ASCII values, and processing user input one character at a time.

What is char?

A char stores a single character enclosed in single quotes. For example:

#include <iostream>
 
int main() {
    char grade = 'A';
    std::cout << "Grade: " << grade << std::endl;
    return 0;
}

Character Literals

Character literals must be enclosed in single quotes:

• 'A', 'z', '5', '$' are all valid
• "A" (double quotes) is a string literal, not a character

ASCII Values

Each char in C++ is internally represented as an ASCII value (an integer). You can use a char like a number or convert between char and int.

#include <iostream>
 
int main() {
    char letter = 'B';
    std::cout << "Character: " << letter << ", ASCII: " << int(letter) << std::endl;
    return 0;
}

Output:

Character: B, ASCII: 66

Declaring and Initializing char

You can declare a char variable and optionally initialize it during declaration:

#include <iostream>
 
int main() {
    char symbol = '#';
    std::cout << "Symbol: " << symbol << std::endl;
    return 0;
}

Working with Characters

Characters can be incremented, compared, and manipulated using arithmetic and relational operators. This is possible because characters are internally just integer values.

#include <iostream>
 
int main() {
    char ch = 'a';
    std::cout << "Original: " << ch << std::endl;
    ch++;
    std::cout << "After Increment: " << ch << std::endl;
    return 0;
}

Output:

Original: a
After Increment: b

Character Input and Output

You can use std::cin and std::cout to accept and display characters.

#include <iostream>
 
int main() {
    char initial;
    std::cout << "Enter your initial: ";
    std::cin >> initial;
 
    std::cout << "You entered: " << initial << std::endl;
    return 0;
}

Character Classification (Optional)

You can use functions from <cctype> to test or transform characters:

• isalpha(ch) – checks if alphabet
• isdigit(ch) – checks if digit
• toupper(ch) – converts to uppercase
• tolower(ch) – converts to lowercase

#include <iostream>
#include <cctype>
 
int main() {
    char input = 'g';
 
    std::cout << "Uppercase: " << char(toupper(input)) << std::endl;
    std::cout << "Is Digit? " << isdigit(input) << std::endl;
 
    return 0;
}

Practice Problem 1: Character to ASCII

Write a program that accepts a character and prints its ASCII code.

#include <iostream>
 
int main() {
    char c;
    std::cout << "Enter a character: ";
    std::cin >> c;
 
    std::cout << "ASCII value: " << int(c) << std::endl;
    return 0;
}

Practice Problem 2: Is Uppercase or Lowercase?

Determine whether a given character is uppercase, lowercase, or neither.

#include <iostream>
 
int main() {
    char ch;
    std::cout << "Enter a character: ";
    std::cin >> ch;
 
    if (ch >= 'A' && ch <= 'Z')
        std::cout << "Uppercase" << std::endl;
    else if (ch >= 'a' && ch <= 'z')
        std::cout << "Lowercase" << std::endl;
    else
        std::cout << "Not an alphabet" << std::endl;
 
    return 0;
}

Practice Problem 3: Print A–Z Using Loop

Print all uppercase letters from A to Z using a for loop.

#include <iostream>
 
int main() {
    for (char c = 'A'; c <= 'Z'; c++) {
        std::cout << c << " ";
    }
    return 0;
}

Summary

The char data type plays a vital role in character-based operations and is the building block for more complex text structures like strings.