Java - Initialize a HashMap of HashMaps

Question

I am new to java and practicing by creating a simplistic NaiveBayes classifier. I am still new to object instantiation, and wonder what to do to initialize a HashMap of Has

Answer 1

Yes, you need to initialize it.

class_feature_counts = new HashMap>();

When you want to add a value to class_feature_counts, you need to instantiate it too:

HashMap val = new HashMap();
// Do what you want to do with val
class_feature_counts.put("myKey", val);