Intent for activity navigation in Android Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

What happens when this Intent code runs?

Consider this Kotlin code inside an Android activity. What will the user see after clicking the button?

Android Kotlin

val intent = Intent(this, SecondActivity::class.java)
startActivity(intent)

A The app closes immediately.

B The app opens SecondActivity screen.

C The app shows an error message.

D Nothing happens; the screen stays the same.

💡 Hint

Intent is used to start a new screen (activity).

The Intent specifies SecondActivity as the target, so startActivity launches that screen.

📝 Syntax

intermediate

Which option correctly creates an Intent to start DetailActivity?

Choose the correct Kotlin code snippet to start DetailActivity from the current activity.

A

val intent = Intent(this, DetailActivity::class.java)
startActivity(intent)

B

val intent = Intent(DetailActivity::class.java, this)
startActivity(intent)

C

val intent = Intent(this, "DetailActivity")
startActivity(intent)

D

val intent = Intent(this)
startActivity(DetailActivity::class.java)

💡 Hint

Intent constructor needs context and target activity class.

Option A correctly uses 'this' as context and DetailActivity::class.java as target.

❓ lifecycle

advanced

What happens to the current activity after startActivity(intent)?

After calling startActivity(intent) to open a new activity, what is the state of the current activity?

A It is restarted.

B It is destroyed immediately.

C It is paused and stopped but remains in the back stack.

D It becomes invisible and removed from memory.

💡 Hint

Think about Android activity lifecycle when switching screens.

The current activity is paused and stopped but kept in the back stack for possible return.

🔧 Debug

advanced

Why does this Intent code cause a crash?

Given this code snippet, why does the app crash when startActivity is called? val intent = Intent(this, SecondActivity::class.java) startActivity(intent)

Android Kotlin

class FirstActivity : AppCompatActivity() {
  fun openSecond() {
    val intent = Intent(this, SecondActivity::class.java)
    startActivity(intent)
  }
}

class SecondActivity : AppCompatActivity() {}

A SecondActivity is not declared in AndroidManifest.xml.

B Intent constructor parameters are reversed.

C startActivity is called outside an activity context.

D SecondActivity class is missing a constructor.

💡 Hint

Android requires all activities to be registered in the manifest.

If SecondActivity is not in the manifest, the system cannot start it, causing a crash.

🧠 Conceptual

expert

What is the purpose of Intent flags in activity navigation?

Why would a developer add flags like FLAG_ACTIVITY_CLEAR_TOP to an Intent before starting an activity?

A To pass data between activities securely.

B To change the theme of the new activity dynamically.

C To delay the start of the activity until a condition is met.

D To control how activities are launched and manage the back stack behavior.

💡 Hint

Flags affect how Android handles activity instances and navigation history.

Flags like FLAG_ACTIVITY_CLEAR_TOP modify the back stack to avoid duplicate activities or clear existing ones.