This sample demonstrates how to query a feature layer via feature table. The sample provides a search bar on the top, where you can input the name of a US State. When you hit search the app performs a query on the feature table and highlights the state geometry.
How it works
When you hit the search button, the app creates an AGSQueryParameter object and specifies the whereClause on it, using the text you provided. It then fires the query on the feature table using the queryFeaturesWithParameters:completion: method. In the completion block it gets back an AGSFeatureQueryResult. Checking the enumerator, if it finds a feature then it highlights the geometry by using selectFeatures method on feature layer.