App size optimization in Android Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable ProGuard for app size optimization in the build.gradle file.

Android Kotlin

android {
    buildTypes {
        release {
            minifyEnabled = [1]
        }
    }
}

Drag options to blanks, or click blank then click option'

A"true"

Bfalse

Ctrue

D"false"

Attempts:

3 left

💡 Hint

Common Mistakes

Using string values like "true" instead of boolean true.

Setting minifyEnabled to false disables code shrinking.

Setting minifyEnabled to true enables code shrinking and obfuscation, which helps reduce app size.

2fill in blank

medium

Complete the code to exclude unused resources during build to reduce app size.

Android Kotlin

android {
    buildTypes {
        release {
            shrinkResources = [1]
        }
    }
}

Drag options to blanks, or click blank then click option'

Atrue

Bfalse

C"false"

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Using string values instead of boolean.

Setting shrinkResources to false disables resource shrinking.

Setting shrinkResources to true removes unused resources, helping to reduce app size.

3fill in blank

hard

Fix the error in the Kotlin code to load only necessary native libraries to reduce app size.

Android Kotlin

System.loadLibrary([1])

Drag options to blanks, or click blank then click option'

A"native-lib"

Blibnative

C"libnative"

Dnative-lib

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the library name without quotes causes a compile error.

Including the lib prefix or file extension is incorrect.

The System.loadLibrary function requires the library name as a string with quotes, without the lib prefix or file extension.

4fill in blank

hard

Fill both blanks to configure ABI splits to reduce APK size by targeting specific CPU architectures.

Android Kotlin

android {
    splits {
        abi {
            enable = [1]
            reset()
            include [2]
        }
    }
}

Drag options to blanks, or click blank then click option'

Atrue

Bfalse

C["armeabi-v7a", "arm64-v8a"]

D["x86", "mips"]

Attempts:

3 left

💡 Hint

Common Mistakes

Setting enable to false disables ABI splits.

Including uncommon or unsupported ABIs.

Enabling ABI splits with true and including common architectures like armeabi-v7a and arm64-v8a helps reduce APK size by building only for those CPUs.

5fill in blank

hard

Fill all three blanks to create a ProGuard rule that keeps only the necessary classes and removes unused code.

Android Kotlin

-keep class [1] {
    [2];
}
-dontwarn [3]

Drag options to blanks, or click blank then click option'

Acom.example.app.MainActivity

Bpublic *

Ccom.example.app.**

Dandroid.support.**

Attempts:

3 left

💡 Hint

Common Mistakes

Using wildcard for class name instead of specific class.

Not specifying members to keep.

Ignoring warnings from support libraries.

This ProGuard rule keeps the MainActivity class and all its public members, and suppresses warnings for the Android support library to avoid build errors.