Java Code Example: Floyd’s Triangle

This program prints a Floyd’s Triangle, which is a right-angled triangular array of natural numbers. The program prompts the user to enter the number of rows they want in the Floyd’s Triangle, and then prints the triangle to the console.

Code Example

class FloydTriangle {
	public static void main(String[] args) {
		int i, j, k = 1;
		Scanner reader = new Scanner(System.in);

		System.out.print("Enter number of rows of floyd`s trangle: ");
		int n = reader.nextInt();
		reader.close();
		
		for (i = 1; i <= n; i++) {
			for (j = 1; j <= i; j++) {
				System.out.print(k + " ");
				k++;
			}
			System.out.println();
		}
	}
}

Output

Enter number of rows of floyd`s trangle: 10
1 
2 3 
4 5 6 
7 8 9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44 45 
46 47 48 49 50 51 52 53 54 55 

Code Explanation

Here’s how the program works:

• The program prompts the user to enter the number of rows they want in the Floyd’s Triangle using the System.out.print() method and reads the input using the Scanner class.
• The program uses a loop to print each row of the triangle.
• The outer loop iterates over the rows of the triangle, from 1 to the user-specified number of rows.
• The inner loop iterates over the columns of the triangle, from 1 to the current row number.
• For each position in the triangle, the current value of k is printed using the System.out.print() method, followed by a space.
• After printing all the values in the current row, a newline character is printed using the System.out.println() method to move to the next row.
• The value of k is incremented after printing each number in the triangle to ensure that the next number printed is the next natural number.

As you can see, the program prints a right-angled triangular array of natural numbers with the user-specified number of rows.