Program to Print Triangle Pattern in java

Printing various patterns in any programming language gives a good start to that language, by printing those patterns we can practice more and its also an important tool to judge your loop knowledge! So today we will learn how to make triangle patterns in JAVA. Many interesting triangle patterns can be made using programming, but in this post I will show you how to make equilateral triangle pattern using Java Language.

1. Lets create a perfect triangle, for that here's a java program source code:

import java.io.*;
public class triangle {
    public static void main ( String arg[] ){
        InputStreamReader istream = new InputStreamReader(System.in) ;
        BufferedReader read = new BufferedReader(istream) ;
        System.out.print("Enter Triangle Size : ");
        int num=0;
        try{
            num=Integer.parseInt( read.readLine() );
        } catch(Exception Number){
            System.out.println("Invalid Number!");
        }
            for(int i=1;i<=num;i++){
                for(int j=1;j<num-(i-1);j++){
                    System.out.print(" ");
                }
                for(int k=1;k<=i;k++){
                    System.out.print("*");
                    for(int k1=1;k1<k;k1+=k){

                        System.out.print("*");
                    }
                }
                System.out.println();
            }
    }
}

Output of the above program :

2. Now lets create an upside down triangle and to do so, Here's the code :

import java.io.*;
public class triangle {
    public static void main ( String arg[] ){
        InputStreamReader istream = new InputStreamReader(System.in) ;
        BufferedReader read = new BufferedReader(istream) ;
        System.out.print("Enter Triangle Size : ");
        int num=0;
        try{
            num=Integer.parseInt( read.readLine() );
        } catch(Exception Number){
            System.out.println("Invalid Number!");       
            for(int i=1;i<=num;i++){
                for(int j=i;j>1;j--){
                    System.out.print(" ");
                }
                for(int k=1;k<=num-(i-1);k++){
                    System.out.print("*");
                    for(int k1=1;k1<k;k1+=k){
                        System.out.print("*");
                    }
                }
                System.out.println();          
    }
}

Output of the above program :

Now lets do the same thing in a  different way

3. Perfect triangle made by placing blank spaces, Here's the code :

import java.io.*;
public class triangle {
    public static void main ( String arg[] ){
        InputStreamReader istream = new InputStreamReader(System.in) ;
        BufferedReader read = new BufferedReader(istream) ;
        System.out.print("Enter Triangle Size : ");
        int num=0;
        try{
            num=Integer.parseInt( read.readLine() );
        } catch(Exception Number){
            System.out.println("Invalid Number!");
        }
            for(int i=1;i<=num;i++){
                for(int j=1;j<=num-(i-1);j++){
                    System.out.print("*");
                    if(j==num-(i-1)){
                        for(int k=1;k<=i;k+=1){
                            System.out.print(" ");
                        }
                        for(int s=1;s<i;s++){
                            System.out.print(" ");
                        }
                        for(int l=1;l<=num-(i-1);l++){
                            System.out.print("*");
                        }
                    }
                }
                System.out.println();
            }
    }
}

Output of the above program : 

4. Upside down triangle made by placing blank spaces, Here's the code :

import java.io.*;
public class triangle4 {
    public static void main ( String arg[] ){
        InputStreamReader istream = new InputStreamReader(System.in) ;
        BufferedReader read = new BufferedReader(istream) ;
        System.out.print("Enter Triangle Size : ");
        int num=0;
        try{
            num=Integer.parseInt( read.readLine() );
        } catch(Exception Number){
            System.out.println("Invalid Number!");
        }
            for(int i=1;i<=num;i++){
                for(int j=num-i;j<num;j++){
                    System.out.print("*");
                    if(j==num-1){
                        for(int k=i;k<=j+1;k+=1){
                            System.out.print(" ");
                        }
                        for(int s=1;s<num-(i-1);s++){
                            System.out.print(" ");
                        }
                        for(int l=num-i;l<num;l++){
                            System.out.print("*");
                        }
                    }              
                System.out.println();
            }
    }
}

Output of the above program : 

You can create triangle of any size ( size here means number of lines ) using these codes.

Various patterns can be printed in Java for more such interesting patterns keep watching the blog!

If you are looking for any other triangle pattern then comment below, we will provide your code as soon as possible!