Feature flags concept in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a feature flag boolean variable in Spring Boot.

Spring Boot

private boolean [1] = true;

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

AfeatureEnabled

BisActive

CenableFeature

DflagActive

Attempts:

3 left

💡 Hint

Common Mistakes

Using vague variable names that don't indicate a feature flag.

Using non-boolean types for feature flags.

The variable enableFeature clearly indicates a feature flag status in boolean form.

2fill in blank

medium

Complete the code to check if the feature flag is enabled before executing the feature.

Spring Boot

if ([1]) {
    // execute feature code
}

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

AfeatureFlag

BisFeatureOn

CfeatureActive

DenableFeature

Attempts:

3 left

💡 Hint

Common Mistakes

Using variables that are not declared or unrelated.

Using non-boolean expressions in the if condition.

The condition checks the enableFeature boolean to decide if the feature runs.

3fill in blank

hard

Fix the error in the feature flag annotation to enable conditional bean loading.

Spring Boot

@ConditionalOnProperty(name = "[1]", havingValue = "true")
@Bean
public FeatureService featureService() {
    return new FeatureService();
}

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

Afeature.enabled

BfeatureFlag

CenableFeature

DfeatureActive

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names instead of property keys.

Missing quotes or incorrect property names.

The property name feature.enabled matches the standard naming convention for feature flags in Spring Boot configuration.

4fill in blank

hard

Fill both blanks to define a feature flag property and inject its value into a Spring component.

Spring Boot

@Value("$[1]")
private boolean [2];

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

Afeature.enabled

BenableFeature

CfeatureFlag

DisFeatureActive

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing property names and variable names.

Forgetting the ${} syntax around the property.

The property feature.enabled is injected into the boolean variable enableFeature to control the feature.

5fill in blank

hard

Fill all three blanks to create a feature flag configuration class with a default value and getter method.

Spring Boot

public class FeatureConfig {
    @Value("$[1]:[2]")
    private boolean [3];

    public boolean isFeatureEnabled() {
        return [3];
    }
}

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

Afeature.enabled

Bfalse

CenableFeature

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the default value after the colon.

Using inconsistent variable names between declaration and getter.

The property feature.enabled is injected with a default value false into the boolean enableFeature. The getter returns this flag.