import com.optimizely.ab.Optimizely;
    
    Optimizely optimizely = Optimizely.builder(datafile).build();
    
    
// Activate an experiment
    Variation variation = optimizely.activate("my_experiment", "user_123");
    
    if (variation != null) {
      if (variation.is("variation_a")) {
        
// Execute code for variation A
      } else if (variation.is("variation_b")) {
        
// Execute code for variation B
      }
    } else {
      
// Execute default code
    }
    
    
// Track an event
    optimizely.track("purchase_completed", "user_123");
            
          

            
    import "optimizely"
    
    project = Optimizely::Project.new(datafile)
    
    
# Activate an experiment
    variation = project.activate('my_experiment', 'user_123')
    
    if variation == 'variation_a'
      
# Execute code for variation A
    elsif variation == 'variation_b'
      
# Execute code for variation B
    else
      
# Execute default code
    end
    
    
# Track an event
    project.track('purchase_completed', 'user_123')
            
          

            
    var optimizely = require('optimizely-server-sdk');
    
    var optimizely = optimizely.createInstance({ datafile: datafile });
    
    
// Activate an experiment
    var variation = optimizely.activate('my_experiment', 'user_123');
    
    if (variation === 'variation_a') {
      
// Execute code for variation A
    } else if (variation === 'variation_b') {
      
// Execute code for variation B
    } else {
      
// Execute default code
    }
    
    
// Track an event
    optimizely.track('purchase_completed', 'user_123');
            
          

            
    use Optimizely\Optimizely;
    
    
// Initialize an Optimizely client
    $optimizelyClient = new Optimizely($datafile);
    
    
// Activate an experiment
    $variation = $optimizelyClient->activate('my_experiment', 'user_123');
    
    if ($variation == 'variation_a') {
      
// Execute code for variation A
    } elseif ($variation == 'variation_b') {
      
// Execute code for variation B
    } else {
      
// Execute default code
    }
    
    
// Track an event
    $optimizelyClient->track('purchase_completed', 'user_123');
            
          

            
    using OptimizelySDK;
    
    
// Initialize an Optimizely client
    Optimizely OptimizelyClient = new Optimizely(datafile);
    
    
// Activate user in an experiment
    var variation = OptimizelyClient.Activate("my_experiment", userId);
    
    if (variation != null) {
        if (variation == "control") {
            
// Execute code for variation A
        }
        else if (variation == "treatment") {
            
// Execute code for variation B
        }
    }
    else {
        
// Execute default code
    }
    
    
// Track conversion event
    OptimizelyClient.Track("my_conversion", userId);
            
          

            
    var optimizely = require('optimizely-client-sdk');
    
    
// Initialize an Optimizely client
    var optimizelyClientInstance = optimizely.createInstance({ datafile: datafile });
    
    
// Alternatively, if you don't use CommonJS or npm, you can install the minified snippet and use the globally exported varible as follows
    var optimizelyClientInstance = window.optimizelyClient.createInstance({ datafile: datafile });
    
    
// Activate user in an experiment
    var variation = optimizelyClientInstance.activate('my_experiment', userId);
    
    if (variation === 'control') {
      
// Execute code for variation A
    } else if (variation === 'treatment') {
      
// Execute code for variation B
    } else {
      
// Execute default code
    }
    
    
// Track conversion event
    optimizelyClientInstance.track('my_conversion', userId);