DRY in Kotlin: Stop Repeating and Start Reusing

DRY — Don’t Repeat Yourself — is one of the most powerful yet overlooked principles in Android and Kotlin development. It’s about writing concise, reusable, and maintainable code instead of duplicating logic across your project.

Kotlin

What is the DRY Principle?

Coined in The Pragmatic Programmer, the DRY principle states:

“Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.”

Kotlin:

Don’t write the same logic twice — extract it, encapsulate it, and reuse it.

Why DRY Matters in Kotlin Projects

Applying DRY properly helps you:

• Reduce bugs from duplicated logic
• Make refactoring easier
• Increase code readability
• Boost developer productivity

Thanks to Kotlin’s expressive syntax, it’s easy to follow DRY — but it’s also easy to break it without realizing.

Sample #1: Repetitive Toast Messages

Bad ❌

fun showLoginSuccess(context: Context) {
    Toast.makeText(context, "Login successful"…