Java Program to Print Mirror Upper Star Triangle Pattern

24 Nov, 2021
The pattern has two parts – both mirror reflections of each other. The base of the triangle has to be at the bottom of the imaginary mirror and the tip at the top.
Illustration:
Input:
size = 7

Output:

      * 
     * * 
    * * * 
   * * * * 
  * * * * * 
 * * * * * * 
* * * * * * * 
* * * * * * * 
 * * * * * * 
  * * * * * 
   * * * * 
    * * * 
     * * 
      * 
Approach: 
Divide pattern into sub-patterns
Divide this into two partsUpper partLower part
Upper part
Lower part
Both parts are a mirror reflection of each other. And each part comprises 2 triangles. Therefore, In total, we have to print 4 triangles to get the desired pattern.
Example 1: Upper Part
Java
// Java Program to Print Upper Part of Mirror Upper Star// Triangle Pattern  // Importing input output classesimport java.io.*;  // Main Classclass GFG {      // Method 1    // To print upper part of the pattern    private static void displayUpperPart(int size)    {          // Declaring variables for rows and columns        // respectively        int m, n;          // Outer loop for rows        for (m = size - 1; m >= 0; m--) {              // Inner loop 1            // to print triangle 1            for (n = 0; n < m; n++) {                  // Printing whitespace                System.out.print(" ");            }              // Inner loop 2            // to print triangle 2            for (n = m; n <= size - 1; n++) {                  // Printing star with whitespace                System.out.print("*"                                 + " ");            }              // By now done with one rpw so next line            System.out.println();        }    }      // Method 2    // Main driver method    public static void main(String[] args)    {        // Declaring and initializing variables to        // size of the triangle        int size = 7;          // Calling the above Method 1 to        // print and display the upper part of triangle        displayUpperPart(size);    }}
  
      * 
     * * 
    * * * 
   * * * * 
  * * * * * 
 * * * * * * 
* * * * * * * 
 
Example 2: Lower Part of the triangle 
 
Java
// Java Program to Print Lower Part of Mirror Upper Star// Triangle Pattern  // Importing input output classesimport java.io.*;  // Main Classclass GFG {      // Method 1    // To print lower part of the pattern    private static void displayLowerPart(int size)    {          // Declaring variables for rows and columns        // respectively        int m, n;          // Outer loop fo Rows        for (m = 1; m <= size; m++) {              // Inner loop 1 to print triangle 3            for (n = 1; n < m; n++) {                  // Printing whitespace                System.out.print(" ");            }              // Inner loop 2 to print triangle 4            for (n = m; n <= size; n++) {                  // Printing star and whitespace                System.out.print("*"                                 + " ");            }              // By now done with one row so new line            System.out.println();        }    }      // Method 2    // Main driver method    public static void main(String[] args)    {        // Declaring and initializing variable to        // size of the triangle        // This is number of rows        int size = 7;          // Calling the above Method1        // to display lower part of the triangle        displayLowerPart(size);    }}
  
* * * * * * * 
 * * * * * * 
  * * * * * 
   * * * * 
    * * * 
     * * 
      * 
 
Example 3: Complete Mirror Upper Star Triangle Pattern
 
Java
// Java Program to Print Mirror upper Star triangle Pattern  // Importing input output classesimport java.io.*;  // Main Classpublic class GFG {      // Method 1    // To print upper part of the pattern    private static void displayUpperPart(int size)    {          // Declaring variables for rows and columns        // respectively        int m, n;          // Outer loop for rows        for (m = size - 1; m >= 0; m--) {              // Inner loop 1            for (n = 0; n < m; n++) {                  // Printing whitespace                System.out.print(" ");            }              // Inner loop 2            for (n = m; n <= size - 1; n++) {                  // Printing star with whitespace                System.out.print("*"                                 + " ");            }              // By now we are done with one row so new line            System.out.println();        }    }      // Method 2    // To print lower part of the pattern    private static void displayLowerPart(int size)    {          // Declaring variables for rows and columns        // respectively        int m, n;          // Outer loop for rows        for (m = 1; m <= size; m++) {              // Inner loop 1            for (n = 1; n < m; n++) {                  // Printing whitespace                System.out.print(" ");            }              // Inner loop 2            for (n = m; n <= size; n++) {                  // Printing star and whitespace                System.out.print("*"                                 + " ");            }              // By now we are done with one row so new line            System.out.println();        }    }      // Method 3    // Main driver method    public static void main(String[] args)    {        // Declaring and initializing variable to        // size of the triangle        int size = 7;          // Calling Method 1 to        // display the upper part        displayUpperPart(size);          // Calling Method 2 to        // display lower part        displayLowerPart(size);    }}
  
      * 
     * * 
    * * * 
   * * * * 
  * * * * * 
 * * * * * * 
* * * * * * * 
* * * * * * * 
 * * * * * * 
  * * * * * 
   * * * * 
    * * * 
     * * 
      * 
 
hritikbhatnagar2182
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