What are View Binding and Data Binding in Android? · IT Interview Practice

What are View Binding and Data Binding in Android?

View Binding and Data Binding are Android features for connecting code to views in XML layouts more safely and conveniently than the old findViewById. View Binding provides type-safe view references; Data Binding additionally binds data directly to layouts.

The problem: findViewById

text

The old way: findViewById to get view references:
  val button = findViewById<Button>(R.id.myButton)
  ✗ verbose; NOT type-safe (cast errors); NOT null-safe (wrong id → null → crash at runtime)
→ View/Data Binding solve these.

View Binding — type-safe view references

kotlin

// View Binding generates a binding class per layout with typed references to its views
val binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
binding.myButton.setOnClickListener { /* ... */ }   // typed, null-safe, no findViewById
binding.titleText.text = "Hello"
// → type-safe (compile-checked), null-safe, concise — the recommended replacement for findViewById

xml

<!-- Data Binding lets you bind data/expressions directly in the layout XML -->
<TextView android:text="@{user.name}" />        <!-- binds to a user object's name -->
<Button android:onClick="@{() -> viewModel.submit()}" />

text

DATA BINDING (more powerful than View Binding):
  → bind layout views directly to data/ViewModels in XML (expressions, two-way binding)
  → can reduce UI-update boilerplate; supports observable data → UI auto-updates
  → more complex; View Binding is simpler and often sufficient
→ Modern apps increasingly use Jetpack COMPOSE instead (no XML binding needed).

What are View Binding and Data Binding in Android?

The problem: findViewById

View Binding — type-safe view references

Data Binding — bind data directly in XML

Why it matters

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