Checking if key exists in cache¶
This API request checks if an object exists in cache. If object is present in cache, the method returns true, otherwise - false. All methods are available via Backendless.Cache.[methodname]
accessor:
// synchronous method public Boolean Contains( String key ) // asynchronous method public void Contains( String key, AsyncCallback<Boolean> callback )
where:
Argument | Description |
---|---|
key |
identifies the object to check in cache. |
callback |
the callback used for asynchronous calls to deliver result or fault to the calling program |
Example¶
AsyncCallback<Boolean> callback = new AsyncCallback<Boolean>( result => { System.Console.WriteLine( "[ASYNC] object exists in cache - " + result ); }, fault => { System.Console.WriteLine( "Error - " + fault ); } ); // get object from cache asynchronously Backendless.Cache.Contains( "firstorder", callback ); // get object from cache synchronously Boolean objectExists = Backendless.Cache.Contains( "firstorder" ); System.Console.WriteLine( "[SYNC] object exists in cache - " + objectExists );