Day 12 – Star Pattern Problems Solution

Today, as part of my Namaste JavaScript learning journey (Day 12), I explored and solved some classic pattern problems in JavaScript. These are simple yet powerful exercises that help build logical thinking and comfort with loops.

✅ Topics Covered:

• Nested Loops in JavaScript
• Printing patterns with * and numbers
• Loop logic and formatting output

📌 Problem 1: Print the Star Square

Print a square pattern made of *, where the number of rows and columns are provided as input.

💡 Approach:

We use a nested loop:

• Outer loop runs for each row.
• Inner loop runs for each column, appending a * to the output string.
• After each row, we add a newline \n.

📥 Input:

Number_Of_Row = 4, Number_Of_Col = 4 

📥 Output:

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

🧪 Solution:

console.log('+++++++++ Print the Star Square +++++++++'); function Print_Star_Square(Number_Of_Row, Number_Of_Col) { let Star = ""; for (let i = 0; i < Number_Of_Row; i++) { for (let j = 0; j < Number_Of_Col; j++) { Star += '* '; } Star += '\n'; // Move to the next line after each row } return Star; } console.log(Print_Star_Square(4, 4)); console.log('++++++++++++++++++++++++++++++++++++++++++'); 

📌 Problem 2: Right-Angled Star Triangle

Print a right-angled triangle of stars with n rows.

💡 Approach:

• Each row prints one more * than the previous one, starting from 1
• The Outer Loop is Responsive for Row and the Inner Low Responsible for Column.

📥 Input:

n = 4 

📥 Output:

* * * * * * * * * * 

🧪 Solution:

function Print_Right_Angled_Star_Triangle(n) { let Star = ""; for (let i = 0; i < n; i++) { for (let j = 0; j <= i; j++) { Star += '* '; } Star += '\n'; } return Star; } console.log(Print_Right_Angled_Star_Triangle(4)); 

📌 Problem 3: Right-Angled Number Triangle

Print a triangle where each row contains increasing numbers from 1 to the row number.

💡 Approach:

For each row i, we loop from 1 to i+1, adding numbers incrementally.

📥 Input:

n = 4 

📥 Output:

1 12 123 1234 

🧪 Solution:

function Print_Right_Angled_Star_Number_Triangle(n) { let Number = ""; for (let i = 0; i < n; i++) { for (let j = 0; j <= i; j++) { Number += j + 1; } Number += "\n"; } return Number; } console.log(Print_Right_Angled_Star_Number_Triangle(4)); 

///

📌 Problem 4: Right-Angled Triangle of Repeated Numbers

Print a triangle where each row contains repeated numbers equal to the row number.

💡 Approach:

For each row i, print (i+1) repeatedly i+1 times.

📥 Input:

n = 4 

📥 Output:

1 22 333 4444 

🧪 Solution:

function Right_Angled_Triangle_of_Repeated_Numbers(n) { let Number = ""; for (let i = 0; i < n; i++) { for (let j = 0; j <= i; j++) { Number += (i + 1); } Number += "\n"; } return Number; } console.log(Right_Angled_Triangle_of_Repeated_Numbers(4)); 

🧠 Key Concepts Practiced:

• Nested for loops
• String building and formatting output
• Pattern logic using rows and columns
• Console logging for step-by-step output

🚀 What’s Next?

I’ll continue with more pattern problems, string manipulation, and functions in upcoming days. These exercises are helping me build a solid base for real-world JavaScript development.

📝 Follow me for more JavaScript learning logs!
💬 Let me know in the comments: Which pattern did you find most interesting?