C++ Alphabet Pattern Programs

Q: Why does cout << ('A' + col) print a number?

In C++, 'A' + col is an int. The usual arithmetic conversions promote the char before the addition, so the sum is 65, 66, 67… and operator ('A' + col), and cout prints the letter.

Q: What is the difference between cout << letter and cout << '\n'?

cout << letter streams the char and stays on the same line, which is how each letter in a row is placed. cout << '\n' ends the row. Call it once after the inner loop. cout << endl also ends the row and flushes the stream; '\n' is enough for these programs.

Q: What happens if the row count is greater than 26?

Char math continues past 'Z' into other characters. For A–Z demos, keep rows between 1 and 26. After cin >> rows, check failure with if (!(cin >> rows)) before you use the value.

Beginner

6 min read

Updated: Nov 2026

3 examples

char + cout

C++ alphabet pattern programs printed with char and cout

Definition

Definition and Usage

A C++ alphabet pattern is a console program that prints letters in rows. The outer for loop chooses the row. The inner for loop prints each char with cout << letter, then cout << '\n' ends that row.

A char is an integer type, so letter++ walks A, B, C… Adding an int promotes the sum: 'A' + col is an int, and cout prints those digits (65, 66, 67). Cast with static_cast<char>('A' + col) when the shape should stay in A–Z.

Stream a char, not the sum.

cout << letter prints the character. cout << ('A' + col) prints the integer code unless you cast back to char first.

Syntax

C++ Syntax

The same three pieces show up in every program below: a char loop, cout, and a newline after the inner loop.

C++

#include <iostream>
using namespace std;

for (char end = 'A'; end <= 'E'; end++) {
    for (char letter = 'A'; letter <= end; letter++)
        cout << letter;   // same line
    cout << '\n';        // end the row
}

Reference

How C++ Prints a Letter

Map each part of the console shape to a C++ type or stream insertion.

Piece	C++	What it does
Letter	`char letter = 'A';`	Integer type that `cout` prints as a character
Next letter	`letter++`	A becomes B on the same row
Jump	`static_cast<char>('A' + col)`	`'A' + col` is an `int`; the cast makes it a letter again
Same line	`cout << letter`	No newline between letters
New row	`cout << '\n'`	Finish the row
Flush	`cout << endl`	Also ends the row, and flushes the stream
Indent	`cout << ' '`	Leading spaces for pyramids
A–Z slice	`letters.substr(0, n)`	Same growing row from a `std::string`

Code

C++ Examples

Three programs. Each one changes only the C++ that picks the letter or the space.

Example 1 — Grow a row with a `char` loop

The outer char is the last letter on the row. The inner loop restarts at 'A'.

C++

#include <iostream>
using namespace std;

int main() {
    for (char end = 'A'; end <= 'E'; end++) {
        for (char letter = 'A'; letter <= end; letter++)
            cout << letter;
        cout << '\n';
    }
    return 0;
}

How It Works

end runs from 'A' to 'E', one row per letter.
The inner loop prints 'A' through end, so the row is A…end.
cout << letter stays on the line; cout << '\n' starts the next row.

Example 2 — Cast the sum back to `char`

Skip the running char. Compute the letter from the column index.

C++

#include <iostream>
using namespace std;

int main() {
    int rows = 4;

    for (int row = 0; row < rows; row++) {
        for (int col = 0; col <= row; col++)
            cout << static_cast<char>('A' + col);
        cout << '\n';
    }
    return 0;
}

How It Works

'A' + col promotes to int.
static_cast<char> turns that sum back into a letter before cout sees it.
Without the cast, the same line prints 65, 6566, and so on.

Example 3 — Indent with `cout << ' '`

Print spaces before the letters so the triangle sits on the right.

C++

#include <iostream>
using namespace std;

int main() {
    int rows = 4;

    for (int row = 1; row <= rows; row++) {
        for (int space = 1; space <= rows - row; space++)
            cout << ' ';

        for (int col = 0; col < row; col++)
            cout << static_cast<char>('A' + col);

        cout << '\n';
    }
    return 0;
}

How It Works

The first inner loop prints rows - row space characters.
The second loop prints letters with the same static_cast<char>.
Fewer spaces and more letters on each later row pull the shape right.

Programs

34 C++ Alphabet Pattern Programs

Each card is a full C++ program: nested for loops, char math, and the letters cout prints. Open one for the walkthrough.

C++ Alphabet Pattern Programs

Definition and Usage

C++ Syntax

How C++ Prints a Letter

C++ Examples

Example 1 — Grow a row with a char loop

How It Works

Example 2 — Cast the sum back to char

How It Works

Example 3 — Indent with cout << ' '

How It Works

34 C++ Alphabet Pattern Programs

Frequently Asked Questions

Related C++ Topics

Alphabet Pattern 1

Number Patterns

Star Patterns

C++ Strings

Next: Alphabet Pattern 1

About the author

Example 1 — Grow a row with a `char` loop

Example 2 — Cast the sum back to `char`

Example 3 — Indent with `cout << ' '`