Cannot invoke "java.util.HashMap.put(Object, Object)" because "this.scoreMap" is null

This error message indicates that you are trying to add a key-value pair to a HashMap object (using the put() method), but the HashMap object has not been initialized yet.

To fix this error, you need to create a new instance of the HashMap object before adding any key-value pairs to it. For example:

Map<String, Integer> scoreMap = new HashMap<>();
scoreMap.put("John", 80);

This code creates a new HashMap object and adds a key-value pair to it. Make sure you initialize the HashMap object before trying to add any values to it.