Java code to hollow triangle pattern

In this tutorial, we will discuss Java code to hollow triangle pattern

We will learn how to create hollow triangle pattern in Java language using nested for loop

Program 1

Code to Hollow triangle pattern 1

Java program to display hollow mirrored right triangle star pattern

import java.util.Scanner;
public class JavaHollowPattern1{
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=i; j<=rows; j++){
     System.out.print(" ");//print space
  }
  for(int j=1; j<=i; j++){
  
  if(i==rows || j==1 || j==i){
     System.out.print("*");//print star
     }
     else{
     System.out.print(" ");
}
}
System.out.println();//move to next line
}
}
}

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

Java code to hollow triangle pattern — Output

Program 2

Code to Hollow triangle pattern 2

Java program to display hollow inverted right triangle star pattern

import java.util.Scanner;
public class JavaHollowPattern2{
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 from user
for(int i=1; i<=rows; i++){//parent for loop lterate rows
  for(int j=i; j<=rows; j++){
  
  if(i==1 || j==i || j==rows){
     System.out.print("*"); //print star
     }
     else{
     System.out.print(" ");
}

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

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

Program 3

Code to Hollow triangle pattern 3

Java program to display hollow inverted mirrored right triangle star pattern

import java.util.Scanner;
public class JavaHollowPattern3{
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 from user
for(int i=1; i<=rows; i++){//parent for loop lterate rows
  for(int j=1; j<=i; j++){
     System.out.print(" ");//print space
  }
  for(int j=i; j<=rows; j++){
  
  if(j==i || j==rows || i==1){
     System.out.print("*");
     }
     else{
     System.out.print(" ");
}
}
System.out.println();//move to next line
}
}
}

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

Program 4

Code to Hollow triangle pattern 4

Java program to display hollow inverted right triangle star pattern

import java.util.Scanner; 
public class JavaHollowPattern{ 
    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 from user 
        for(int i=1; i<=rows; i++){
            //parent for loop lterate rows 
            for(int j=1; j<=i; j++){ if(j==1 || j==i || i==rows){ System.out.print("*"); //print star, when the condiiton is true 
            } 
            else{ System.out.print(" "); } } 
            System.out.println();//move to next line 
            } 
            
        } 
        
    }

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