Passing data between activities in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of Intent extras in Android?

Intent extras are used to pass small amounts of data between activities in an Android app. They act like a bundle of key-value pairs attached to the Intent.

beginner

How do you add data to an Intent before starting a new activity?

Use the putExtra() method on the Intent object, providing a key and a value. For example: intent.putExtra("username", "Alice")

beginner

How does the receiving activity retrieve data passed via Intent extras?

In the receiving activity, call intent.getStringExtra("key") or the appropriate getExtra method inside onCreate() to get the data sent from the previous activity.

intermediate

What happens if you try to get an extra with a key that was not sent?

The getExtra method returns null (or a default value for primitives). Always check for null to avoid crashes.

intermediate

Can you pass complex objects between activities using Intent extras?

Yes, but the objects must implement Parcelable or Serializable interfaces to be passed via Intent extras.

Which method is used to add data to an Intent before starting a new activity?

A putExtra()

B getExtra()

C startActivity()

D setContentView()

putExtra() adds key-value data to the Intent to pass to the next activity.

How do you retrieve a String extra named "user" in the receiving activity?

A startActivity(intent)

B intent.getStringExtra("user")

C getIntent().putExtra("user")

D intent.getExtra("user")

Use intent.getStringExtra("user") to get the String value passed with key "user".

What must a custom object implement to be passed via Intent extras?

A Runnable

B Activity

C View

D Parcelable or Serializable

Custom objects must implement Parcelable or Serializable to be passed between activities.

If you try to get an extra that was not sent, what will happen?

A Starts a new activity

B App crashes immediately

C Returns null or default value

D Throws a compile error

Getting a missing extra returns null or a default value; it does not crash but you should check for null.

Which Android component is responsible for starting a new screen (activity)?

A Intent

B View

C Service

D BroadcastReceiver

Intent is used to start new activities and can carry data between them.

Explain how to pass a username string from one activity to another in Android using Kotlin.

Think about how you attach data to the Intent and how the next screen reads it.

Describe how you would pass a custom data object between activities and what requirements that object must meet.

Consider Android's rules for passing complex data.