Print Inverted Pyramid Star Pattern in Java

Topic

In this program, we will learn how to print an inverted pyramid star pattern using Java. An inverted pyramid is a pattern where the top row contains the most stars, and each subsequent row contains two fewer stars, centered properly using spaces.

This problem helps beginners understand nested loops — one loop for rows and another for handling spaces and stars on each row.

Examples

Example 1 (n = 5):

*********
 *******
  *****
   ***
    *

Example 2 (n = 3):

*****
 ***
  *

Example 3 (Edge Case: n = 1):

*

Interviewer Expectations

The interviewer wants to assess your understanding of:

• Nested for loops
• How to manage spaces and stars for symmetrical patterns
• Basic arithmetic and loop conditions
• Clean code structure and proper indentation

Approach

Let’s break it down:

• We take a number n as the input which represents the number of rows in the pyramid.
• We use an outer loop to control the number of rows.
• For each row:
  • Print spaces on the left to center the stars
  • Then print the stars: number of stars is 2 * i - 1 where i is the current row number from n to 1

Dry Run (n = 3)

Row 1: spaces = 0, stars = 2*3-1 = 5   => *****  
Row 2: spaces = 1, stars = 2*2-1 = 3   =>  ***
Row 3: spaces = 2, stars = 2*1-1 = 1   =>   *

Java Program

 without newline for each star.",
    "After the stars, we move to the next line using System.out.println().",
    "Repeat the above steps for each decreasing row until i = 1.",
    "At the end, we have a complete inverted pyramid pattern printed.",
    "The main method ends here."
  ]'>public class InvertedPyramidPattern {
    public static void main(String[] args) {
        int n = 5;

        for (int i = n; i >= 1; i--) {
            for (int space = 0; space < n - i; space++) {
                System.out.print(" ");
            }

            for (int star = 0; star < 2 * i - 1; star++) {
                System.out.print("*");
            }

            System.out.println();
        }
    }
}

*********
 *******
  *****
   ***
    *

Practice: Inverted Pyramid Star Pattern

Possible Followup Questions with Answers

Q1: How would you print a normal (non-inverted) pyramid star pattern?

You would reverse the loop to go from 1 to n and adjust the space and star logic accordingly:

for (int i = 1; i <= n; i++) {
    for (int space = 0; space < n - i; space++) {
        System.out.print(" ");
    }
    for (int star = 0; star < 2 * i - 1; star++) {
        System.out.print("*");
    }
    System.out.println();
}

Q2: Can you make the stars print with a space in between, like "* * * * *"?

Yes, just print "* " instead of "*" inside the inner loop for stars.

Q3: What if we want the pattern to be left-aligned instead of centered?

Skip printing spaces before stars and just reduce the number of stars per row.

Q4: How do you make the pattern dynamic based on user input?

Use Scanner to read value of n from user:

Scanner sc = new Scanner(System.in);
int n = sc.nextInt();

Q5: What are common mistakes beginners make in such pattern problems?

• Incorrect loop boundaries
• Using System.out.println() instead of System.out.print() inside inner loops
• Getting space and star counts wrong