Java: Display the pattern like a diamond

Last update on May 14 2025 13:01:01 (UTC/GMT +8 hours)

Display Diamond Pattern

Write a Java program to display the pattern like a diamond.

Test Data
Input number of rows (half of the diamond) :7

Pictorial Presentation:

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise21 {

  public static void main(String[] args)
	  
	  
{
   int i,j,r;
   System.out.print("Input number of rows (half of the diamond) : ");
   Scanner in = new Scanner(System.in);
		    r = in.nextInt();
   for(i=0;i<=r;i++)
   {
     for(j=1;j<=r-i;j++)
     System.out.print(" ");
     for(j=1;j<=2*i-1;j++)
       System.out.print("*");
     System.out.print("\n");
   }
 
   for(i=r-1;i>=1;i--)
   {
     for(j=1;j<=r-i;j++)
     System.out.print(" ");
     for(j=1;j<=2*i-1;j++)
       System.out.print("*");
     System.out.print("\n");
   }
 
}
}

Sample Output:

Input number of rows (half of the diamond) : 7                                                                                                       
      *                                                                                                       
     ***                                                                                                      
    *****                                                                                                     
   *******                                                                                                    
  *********                                                                                                   
 ***********                                                                                                  
*************                                                                                                 
 ***********                                                                                                  
  *********                                                                                                   
   *******                                                                                                    
    *****                                                                                                     
     ***                                                                                                      
      *

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to display a diamond pattern using numbers instead of asterisks.
• Write a Java program to generate a diamond pattern with alternating characters in each row.
• Write a Java program to print a diamond pattern using recursion for the upper and lower halves.
• Write a Java program to create a diamond pattern where the number of characters increases and then decreases symmetrically.

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