Java code to triangle number pattern

Java code to triangle number pattern

In this tutorial, we will learn about Java code to triangle number pattern using nested for in Java language

Nested loops are(for, while,do-while) useful to create funny patterns as number patterns alphabet, Star  patterns

We will learn in this tutorial about Triangle number pattern printing using nested for in Java

1. write this program of your text editor
2. save your file name like as class name with .java extension
3. compile the program using Javac compiler
4. finally, run the program (using .class file)

Program 1

Triangle number pattern program 1

import java.util.Scanner;
public class Reverse_Pyramid{
public static void main(String args[]){
int rows;
Scanner s=new Scanner(System.in);
System.out.println("Enter number of rows");
rows=s.nextInt();   //get input from user
for(int i=1; i<=rows; i++){ //parent for loop
//to iterates row
for(int j=1; j<=i; j++){
System.out.print("");

}
for(int k=i; k<=rows; k++){
System.out.print(k+" ");//print number and space

}
System.out.println();//move to next line
}

}

}

When the above code is executed, it produces the following results:

1 2 3 4 5 6 7 8
2 3 4 5 6 7 8
3 4 5 6 7 8
4 5 6 7 8
5 6 7 8
6 7 8
7 8
8

 

Program 2

Triangle number pattern program 2

import java.util.Scanner;
public class JavatrianglePattern2{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
System.out.print("Enter the number of rows: ");
int rows=sc.nextInt();
for(int i=1; i<=rows; i++){//parent for loop lterate rows

  for(int j=1; j<=i; j++){
     System.out.print(j+" ");//print number and space
  }
  for(int j=i-1; j>=1; j--){
  System.out.print(j+" ");
  
}
System.out.println();
}
System.out.println();//move to next line
}
}

When the above code is executed, it produces the following results:

1
1 2 1
1 2 3 2 1 
1 2 3 4 3 2 1
1 2 3 4 5 4 3 2 1
1 2 3 4 5 6 5 4 3 2 1
1 2 3 4 5 6 7 6 5 4 3 2 1
1 2 3 4 5 6 7 8 7 6 5 4 3 2 1
1 2 3 4 5 6 7 8 9 8 7 6 5 4 3 2 1

 

Program 3

Triangle number pattern program 3

import java.util.Scanner;
public class JavatrianglePattern3{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
System.out.print("Enter the number of rows: ");
int rows=sc.nextInt();//get input for rows from user
for(int i=1; i<=rows; i++){//parent for loop lterate rows

  for(int j=i; j>=1; j--){
     System.out.print(j+" ");//print number and space
  }
  System.out.println();//move to next line
}
}
}

When the above code is executed, it produces the following results:

1
2 1
3 2 1
4 3 2 1
5 4 3 2 1
6 5 4 3 2 1
7 6 5 4 3 2 1
8 7 6 5 4 3 2 1
9 8 7 6 5 4 3 2 1

 

Program 4

Triangle number pattern program 4

import java.util.Scanner;
public class JavatrianglePattern4{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
System.out.print("Enter the number of rows: ");
int rows=sc.nextInt();//get input for rows from user
for(int i=1; i<=rows; i++){//parent for loop lterate rows
int count=i;
  for(int j=1; j<=i; j++){
     System.out.print(count+" ");//print number and space
     count=count+rows-j;
  }
  System.out.println();//move to next line
}
}
}

When the above code is executed, it produces the following results:

1 
2 10
3 11 18
4 12 19 25
5 13 20 26 31
6 14 21 27 32 36
7 15 22 28 33 37 40
8 16 23 29 34 38 41 43
9 17 24 30 35 39 42 44 45

 

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