Insert Dimensions to complete Expression/ReferenceType

Question

I\'m a newbie to Java.

I have provided a short snippet from my code for BFS.

public int bfs(Person p, Person q) {
    private HashMap

        

Answer 1

Satyendra Sharma's answer is absolutely correct, but here's some reasoning of what exactly the error message is saying.

The error is caused by using a primitive type, which cannot be used as a generic type argument. For instance, List is incorrect, whereas List is correct. Wrapper classes can be used to wrap the primitive values and yield a reference type, which can be used with generics.

Insert dimensions? What?

The message "Insert dimensions to complete expression/referenceType" is probably because in order for the expression to become valid, the only valid token here is a set of square brackets.

For instance,

HashMap marked;

will just compile fine. This is because, unlike a boolean, a boolean[] is an object.