Get Feature Variable
This topic describes the Get Feature Variable method which evaluates the specified feature variable of a specific variable type and returns its value.
Evaluates the specified feature variable of a specific variable type and returns its value.
This method is used to evaluate and return a feature variable. Multiple versions of this method are available and are named according to the data type they return:
This method takes into account the user attributes passed in, to determine if the user is part of the audience that qualifies for the experiment.
Boolean
Returns the value of the specified Boolean variable.
public @Nullable Boolean getFeatureVariableBoolean(@Nonnull String featureKey,
@Nonnull String variableKey,
@Nonnull String userId,
@Nonnull Map<String, Object> attributes)
Double
Returns the value of the specified double variable.
public @Nullable Double getFeatureVariableDouble(@Nonnull String featureKey,
@Nonnull String variableKey,
@Nonnull String userId,
@Nonnull Map<String, Object> attributes)
Integer
Returns the value of the specified integer variable.
public @Nullable Integer getFeatureVariableInteger(@Nonnull String featureKey,
@Nonnull String variableKey,
@Nonnull String userId,
@Nonnull Map<String, Object> attributes)
String
Returns the value of the specified string variable.
public @Nullable String getFeatureVariableString(@Nonnull String featureKey,
@Nonnull String variableKey,
@Nonnull String userId,
@Nonnull Map<String, String> attributes)
JSON
Returns the value of the specified JSON variable.
public @Nullable OptimizelyJSON getFeatureVariableJSON(@Nonnull String featureKey,
@Nonnull String variableKey,
@Nonnull String userId,
@Nonnull Map<String, ?> attributes)
Version
SDK v3.0, v3.1
Description
Each of the Get Feature Variable methods follows the same logic as Is Feature Enabled:
- Evaluate any feature tests running for a user.
- Check the default configuration on a rollout.
The default value is returned if neither of these are applicable for the specified user, or if the user is in a variation where the feature is disabled.
Important
Unlike Is Feature Enabled, the Get Feature Variable methods do not trigger an impression event. This means that if you are running a feature test, events will not be counted until you call Is Feature Enabled. If you do not call Is Feature Enabled, you will not see any visitors on your results page.
Parameters
Required and optional parameters in Java are listed below.
| Parameter | Type | Description |
|---|---|---|
| featureKey required | string | The feature key is defined from the Features dashboard; see Use feature flags. |
| variableKey required | string | The key that identifies the feature variable. For more information, see: Create feature variables. |
| userId required | string | The user ID string uniquely identifies the participant in the experiment. For more information, see: Handle user IDs. |
| attributes required | map | A map of custom key-value string pairs specifying attributes for the user that are used for Target audiences and results segmentation. Non-string values are only supported in the 3.0 SDK and above. |
Returns
The value of the variable, or null if the feature key is invalid, the variable key is invalid, or there is a mismatch with the type of the variable.
Example
Map<String, Object> attributes = new HashMap<>();
attributes.put("device", "iPhone");
attributes.put("lifetime", 24738388);
attributes.put("is_logged_in", true);
Double featureVariableValue = optimizelyClient.getFeatureVariableDouble("my_feature_key", "double_variable_key", "user_123", attributes);
Side effects
In SDKs v3.1 and later: Invokes the DECISION notification listener if this listener is enabled.
Source files
The language/platform source files containing the implementation for Java is Optimizely.java.
Updated over 2 years ago