// Initialize an Optimizely manager
OPTLYManager *optlyManager = [OPTLYManager init:^(OPTLYManagerBuilder * _Nullable builder) {
    builder.projectId = @"projectId";
}];

// Initialize an Optimizely client by asynchronously downloading the datafile
[optlyManager initializeWithCallback:^(NSError * _Nullable error, OPTLYClient * _Nullable client) {
    // Activate user in an experiment
    OPTLYVariation *variation = [client activate:@"my_experiment" userId:@"userId"];

    if ([variation.variationKey isEqualToString:@"control"]) {
        // Execute code for the control
    } else if ([variation.variationKey isEqualToString:@"treatment"]) {
        // Execute code for the treatment
    } else {
        // Execute default code
    }

    // Track conversion event
    [client track:@"my_conversion" userId:@"userId"];
}];

// Initialize an Optimizely manager
let optimizelyManager : OPTLYManager? = OPTLYManager.init {(builder) in
    builder!.projectId = "projectId"
}

// Initialize an Optimizely client by asynchronously downloading the datafile
optimizelyManager?.initialize(callback: { [weak self] (error, optimizelyClient) in

    // Activate user in an experiment
    if let variation = optimizelyClient?.activate("my_experiment", userId: "userId")
    {
        if (variation.variationKey == "control") {
            // Execute code for the control
        }
        else if (variation.variationKey == "treatment") {
            // Execute code for the treatment
        }
    } else {
        // execute default code
    }

    // Track conversion event
    optimizelyClient?.track("my_conversion", userId: "userId")
})

import com.optimizely.ab.Optimizely;

// Get an Optimizely client
OptimizelyClient optimizelyClient = optimizelyManager.getOptimizely();

// Activate user in an experiment
Variation variation = optimizelyClient.activate("my_experiment", "user_id");

if (variation != null) {
  if (variation.is("control")) {
    // Execute code for variation A
  } else if (variation.is("treatment")) {
    // Execute code for variation B
  }
} else {
  // Execute default code
}

// Track conversion event
optimizelyClient.track("my_conversion", user_id);