Java Program to print Floyd’s Triangle

Write a Java Program to print Floyd’s Triangle with example. The Floyd’s Triangle is a right angled triangle with an array of natural numbers.

Java Program to print Floyd’s Triangle

This Java program allows the user to enter the maximum number of rows he/she want to print as Floyd’s triangle. Then, this program prints Floyd’s triangle of natural numbers until it reaches the user-specified rows.

// Java Program to print Floyd’s Triangle
package ShapePrograms;

import java.util.Scanner;

public class FloydTriangle {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int  rows, i,  j, number = 1;
		sc = new Scanner(System.in);		
		System.out.println(" Please Enter the Number of Rows you wish to see in FloydTriangle:  ");
		rows = sc.nextInt();
		System.out.println("---- Printing FLOYD'S Triangle ------");
		for ( i = 1 ; i <= rows; i++ ){
			for ( j = 1 ; j <= i; j++ ) {
				System.out.format("%d ", number);
				number++;
			}
			System.out.println("");
		}
	}
}
Java Program to print Floyd Triangle 1

The following statements will allow the User to enter the range or maximum Number of rows he/she want to print.

System.out.println(" Please Enter the Number of Rows you wish to see in FloydTriangle:  ");
rows = sc.nextInt();

Now let us see the Nested for loop in Java

for ( i = 1 ; i <= rows; i++ ){
	for ( j = 1 ; j <= i; j++ ) {
		System.out.format("%d ", number);
		number++;
	}
	System.out.println("");
}

Floyd’s Triangle Outer For Loop – First Iteration

From the above screenshot, please observe that the value of i is 1 and Rows is 5. So, the condition (i <= 5) is True, and it will enter into second for loop.

Inner For Loop – First Iteration

The j value is 1, and the condition (j <= 1) is True. So, it will start executing the statements inside the loop. The following statement will print Number as Output, and we all know that Number = 1. So, 1 printed.

System.out.format("%d ", number);

The below statement will increment the Value of Number by 1 using the Increment Operator

number++;

Inner For Loop – Second Iteration: The j value will be 2, and the condition (2 <= 1) is False so that it will exit from the second loop.

The following statement is to terminate the current line

System.out.println("");

Outer For Loop – Second Iteration: The value of i will be 2, and the condition (2 <= 5) is True. So, it will enter into second for loop.

Inner For Loop – First Iteration

The value of j is 1 ,and the condition (1 <= 2) is True. So, it will start executing the statements inside the loop. The following statement will print Number as Output, and we all know that Number = 2. So, it prints 2.

System.out.format("%d ", number);

The following statement will increment the Value of Number by 1

number++;

Next, j value will also be incremented by 1.

Inner For Loop – Second Iteration: The value of j is 2, and the condition (2 <= 2) is True. So, it will start executing the statements inside the loop. It means 3 printed.

Inner For Loop – Third Iteration: The j value will be 3, and the condition (3 <= 2) is False. So, it exits from the second loop.

It happens until it reaches 5, and after that, both the Inner Loop and Outer loop terminated.

Java Program to Print Floyd’s Triangle using Functions

This program allows the user to enter the maximum number of rows to print as Floyd’s triangle. Next, this program prints Floyd’s triangle of natural numbers using Functions.

package ShapePrograms;

import java.util.Scanner;

public class FloydTriangleusingMethods {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int  rows;
		sc = new Scanner(System.in);		
		System.out.println(" Please Enter the Number of Rows you wish to see in FloydTriangle:  ");
		rows = sc.nextInt();
		
		System.out.println("---- Printing FLOYD'S Triangle ------");
		FloydTriangle(rows);		
	}
	
	public static void FloydTriangle (int rows)  {
		int  i,  j, number = 1;
		for ( i = 1 ; i <= rows; i++ )  {
			for ( j = 1 ; j <= i; j++ )  {
				System.out.format("%d ", number);
				number++;
			}
			System.out.println("");
		}
	}
}

Java Floyd’s Triangle output

 Please Enter the Number of Rows you wish to see in FloydTriangle:  
10
---- Printing FLOYD'S Triangle ------
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 

When the compiler reaches to FloydTriangle(rows); line then the compiler will immediately jump to below function:

public static void FloydTriangle (int rows)  {

We already explained the LOGIC in the above example.

Java Program to Print Floyd’s Triangle without Natural numbers

This Java program allows the user to enter the number of rows he/she want to display as Floyd’s triangle. In this example, we are going to print Floyd’s triangle using the * symbol. This Java program can also say as printing Right angled triangle with * symbols.

// Floyd’s Triangle program in Java
package ShapePrograms;

import java.util.Scanner;

public class FloydTrianglewithoutNumbers {
	private static Scanner sc;
	
	public static void main(String[] args) {
		int  rows, i,  j;
		sc = new Scanner(System.in);		
		System.out.println(" Please Enter the Number of Rows you wish to see in FloydTriangle:  ");
		rows = sc.nextInt();
		
		System.out.println("---- Printing FLOYD'S Triangle ------");
		for ( i = 1 ; i <= rows; i++ ) {
			for ( j = 1 ; j <= i; j++ ) {
				System.out.format("* ");
			}
			System.out.println("");
		}
	}
}
 Please Enter the Number of Rows you wish to see in FloydTriangle:  
8
---- Printing FLOYD'S Triangle ------
* 
* * 
* * * 
* * * * 
* * * * * 
* * * * * * 
* * * * * * * 
* * * * * * * *