JavaScript Alphabet Pattern 21

Posted in JavaScript Tutorial

Updated on Jan 10, 2024

By Mari Selvan

👁️ 90 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

JavaScript Alphabet Pattern 21

Here`s a program that prints the above alphabet pattern using JavaScript Programming:

example.html

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<!DOCTYPE html>
<html>
<body>

<script>
var i, j;
// First Part
for(i=1; i<=5; i++)
{
 for(j=1; j<i*2; j++)
 {
  if(j % 2 == 0)
   document.write("*");
  else 
   document.write(String.fromCharCode(i+64));
 }
 document.write("<br>");
}
// Second Part
for(i=4; i>=1; i--)
{
 for(j=1; j<i*2; j++)
 {
  if(j % 2 == 0) 
   document.write("*");
  else
   document.write(String.fromCharCode(i+64));
 }
 document.write("<br>");
}
</script>
</body>
</html>

💻 Testing the Program

When you run the above program, it will print the following output:

Output

A
B*B
C*C*C
D*D*D*D
E*E*E*E*E
D*D*D*D
C*C*C
B*B
A

🧠 How the Program Works

Let's break down the logic behind the code:

Initialization:
- var i, j;: Declares two variables i and j to be used in the loops.
First Part (Upper Half):
- The outer loop for(i=1; i<=5; i++) iterates through values of i from 1 to 5.
- The inner loop for(j=1; j<i*2; j++) iterates through values of j from 1 to i * 2 - 1.
- Inside the inner loop, there's an if condition: if(j % 2 == 0). If j is even, it prints an asterisk (*).
- If j is odd, it prints a character using String.fromCharCode(i+64). Here, i+64 converts the value of i to its corresponding uppercase letter in the ASCII table. For example, if i is 1, then the ASCII code for 'A' is 65, and since i+64 is 65, it will print 'A'.
- After the inner loop completes for each i, a line break <br> is printed to move to the next line.
Second Part (Lower Half):
- The second part is similar to the first part but in reverse order. The outer loop for(i=4; i>=1; i--) iterates through values of i from 4 to 1.
- The inner loop for(j=1; j<i*2; j++) iterates through values of j from 1 to i * 2 - 1.
- The if condition and character printing inside the inner loop are the same as in the first part.

💯 Tips for Enhancement:

Explore the versatility of this pattern by adjusting its parameters. Whether you increase or decrease the size, tweak the spacing, or modify the characters used, each change opens up a world of possibilities, allowing you to customize and create your unique visual effects.

✔ Conclusion:

Creating visually appealing patterns is not only a fun endeavour but also a great way to enhance your programming or design skills. We hope this tutorial has inspired you to explore the world of creative coding. Share your creations with us, and let your imagination run wild!

🤗 Closing Call-to-Action:

We'd love to see your unique interpretations of the alphabet pattern. Share your creations in the comments below, and don't hesitate to reach out if you have any questions or suggestions for future tutorials. Happy coding!