You might want to check if the current user is already subscribed to a topic. For example, your application may want to show a "SUBSCRIBE" button for users who have not yet subscribed to a topic and an "UNSUBSCRIBE" button instead for those users who are already subscribed to the topic.
Here is the sample code for checking the subscription status.
Here's a description of the sample code:
Instantiates a topic.
Creates a KiiPushSubscription instance by calling the pushSubscription method.
Calls the isSubscribed method to check if the current user is already subscribed to the topic.