AP Computer Science A Standards: Non-static methods (instance methods) belong to an object and require an instantiated object to be called using the dot operator (e.g., obj.methodName()). A void method does not return a value and cannot be used in expressions. Methods can accept parameters, and the actual parameters (arguments) passed during the method call must match the formal parameters' types, order, and quantity. If an object reference is null, calling an instance method will throw a NullPointerException.