Android build configuration in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the minimum SDK version in the Android build configuration.

Flutter

android {
  defaultConfig {
    minSdkVersion [1]
  }
}

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

A21

BcompileSdkVersion

CtargetSdkVersion

DversionCode

Attempts:

3 left

💡 Hint

Common Mistakes

Using compileSdkVersion instead of minSdkVersion.

Putting a string instead of a number.

The minSdkVersion defines the minimum Android version your app supports. Here, 21 means Android 5.0 Lollipop.

2fill in blank

medium

Complete the code to set the application ID in the Android build configuration.

Flutter

android {
  defaultConfig {
    applicationId "[1]"
  }
}

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

Acom.example.myapp

BminSdkVersion

CversionCode

DtargetSdkVersion

Attempts:

3 left

💡 Hint

Common Mistakes

Using numbers or variables instead of a string.

Confusing applicationId with versionCode.

The applicationId is the unique identifier for your app on the Play Store. It looks like a reversed domain name.

3fill in blank

hard

Fix the error in the code to correctly set the target SDK version.

Flutter

android {
  defaultConfig {
    targetSdkVersion [1]
  }
}

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

AminSdkVersion

B"30"

CcompileSdkVersion

D30

Attempts:

3 left

💡 Hint

Common Mistakes

Putting the SDK version number inside quotes.

Using compileSdkVersion instead of targetSdkVersion.

The targetSdkVersion must be a number without quotes. Using quotes causes a syntax error.

4fill in blank

hard

Fill both blanks to set the version code and version name in the Android build configuration.

Flutter

android {
  defaultConfig {
    versionCode [1]
    versionName "[2]"
  }
}

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

A5

B1.0.0

C21

D2.0

Attempts:

3 left

💡 Hint

Common Mistakes

Putting quotes around versionCode.

Using a number for versionName without quotes.

versionCode is an integer that increments with each release. versionName is a string shown to users.

5fill in blank

hard

Fill all three blanks to configure the compile SDK version, build tools version, and enable multidex.

Flutter

android {
  compileSdkVersion [1]
  buildToolsVersion "[2]"
  defaultConfig {
    multiDexEnabled [3]
  }
}

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

A33

B33.0.0

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Putting quotes around compileSdkVersion or multiDexEnabled.

Using false instead of true for enabling multidex.

compileSdkVersion is the Android API level to compile against (number). buildToolsVersion is the version of build tools (string). multiDexEnabled is a boolean to allow multiple dex files.

Practice

1. What file do you edit to change the Android app ID in a Flutter project?

easy

A. android/gradle.properties

B. lib/main.dart

C. android/app/build.gradle

D. pubspec.yaml

Solution

1. Step 1: Identify where Android app settings are configured

   The Android app ID is set in the Gradle build configuration files.

2. Step 2: Locate the specific file for app-level settings

   The file android/app/build.gradle contains the app ID under the defaultConfig section.

3. Final Answer:

   android/app/build.gradle -> Option C

4. Quick Check:

   App ID set in build.gradle [OK]

Hint: App ID is in app-level build.gradle file [OK]

Common Mistakes:

• Editing pubspec.yaml instead of build.gradle
• Changing main.dart which is for Dart code
• Modifying gradle.properties which is for Gradle settings

2. Which syntax correctly sets the minimum SDK version in android/app/build.gradle?

easy

A. minSdkVersion -> 21

B. minSdkVersion = 21

C. minSdkVersion: 21

D. minSdkVersion 21

Solution

1. Step 1: Understand Gradle syntax for SDK versions

   Gradle uses simple assignment without equals or arrows for SDK versions.

2. Step 2: Identify correct syntax

   The correct syntax is minSdkVersion 21 without equals or colon.

3. Final Answer:

   minSdkVersion 21 -> Option D

4. Quick Check:

   Gradle uses space, not = or : [OK]

Hint: Use space, not equals, for SDK versions in Gradle [OK]

Common Mistakes:

• Using equals sign (=) which causes syntax error
• Using colon (:) which is invalid in Gradle
• Using arrow (->) which is not Gradle syntax

3. Given this snippet in android/app/build.gradle:

defaultConfig {
    applicationId "com.example.app"
    minSdkVersion 19
    targetSdkVersion 33
    versionCode 5
    versionName "1.0.4"
}

What is the app version name that will appear to users?

medium

A. "1.0.4"

B. "1.0.5"

C. "5"

D. "33"

Solution

1. Step 1: Identify versionName in the configuration

   The versionName is set to "1.0.4" which is the user-visible version.

2. Step 2: Differentiate versionCode and versionName

   versionCode is an internal number (5), not shown to users.

3. Final Answer:

   "1.0.4" -> Option A

4. Quick Check:

   versionName is user-visible version [OK]

Hint: versionName shows app version to users [OK]

Common Mistakes:

• Confusing versionCode with versionName
• Using targetSdkVersion as version
• Ignoring quotes around versionName

4. You added minSdkVersion 21 in android/app/build.gradle but get a build error. What is the likely cause?

medium

A. You forgot to update compileSdkVersion to at least 21

B. minSdkVersion must be less than 21

C. You need to add quotes around 21

D. minSdkVersion is set in pubspec.yaml, not build.gradle

Solution

1. Step 1: Understand SDK version dependencies

   The compileSdkVersion must be equal or higher than minSdkVersion.

2. Step 2: Check build.gradle for compileSdkVersion

   If compileSdkVersion is lower than 21, build fails when minSdkVersion is 21.

3. Final Answer:

   You forgot to update compileSdkVersion to at least 21 -> Option A

4. Quick Check:

   compileSdkVersion ≥ minSdkVersion [OK]

Hint: compileSdkVersion must be ≥ minSdkVersion [OK]

Common Mistakes:

• Thinking minSdkVersion must be less than 21
• Adding quotes around numeric SDK versions
• Trying to set minSdkVersion in pubspec.yaml

5. You want to create a new build type called staging in android/app/build.gradle that behaves like debug but with a different app ID suffix. Which snippet correctly adds this?

hard

A. buildTypes {
staging {
extends debug
applicationIdSuffix ".staging"
}
}

B. buildTypes {
staging {
initWith debug
applicationIdSuffix ".staging"
}
}

C. buildTypes {
staging {
copyFrom debug
applicationIdSuffix ".staging"
}
}

D. buildTypes {
staging {
inherit debug
applicationIdSuffix ".staging"
}
}

Solution

1. Step 1: Recall Gradle syntax for copying build types

   Gradle uses initWith to copy settings from another build type.

2. Step 2: Verify correct method and syntax

   initWith debug correctly copies debug settings; applicationIdSuffix ".staging" adds suffix.

3. Final Answer:

   buildTypes { staging { initWith debug applicationIdSuffix ".staging" } } -> Option B

4. Quick Check:

   Use initWith to copy build type [OK]

Hint: Use initWith to clone build types in Gradle [OK]

Common Mistakes:

• Using extends or inherit which are invalid Gradle keywords
• Trying copyFrom which does not exist
• Not adding applicationIdSuffix properly