Why parametized functions make your code cleaner

When you’re new to JavaScript, it’s tempting to write logic directly inside event listeners. It works until your code grows. Soon you’re repeating yourself, fixing bugs in multiple places, and struggling to keep everything in sync. Thats why parametized functions is important.

Take this example of a calculator app. Each button (+, -, ×, /) needs to:

1. Save the first number.

2. Store the operator.

3. Clear the display.

Without parameters, you end up repeating logic:

Instead of repeating the same steps, wrap them into one reusable function with a parameter:

this improves usability because:

DRY Principle (Don’t Repeat Yourself): One function handles all operators.

Easier Maintenance: Change logic once, and every operator updates.

Scalable: Adding more operators (like % or √) is just one line.

Readable: The intent is clear “set operator to X"

I do think parametized functions make your code clean and reusable