Access Designations

As mentioned previously, the plus signs (+) and minus signs (-) to the left of the attributes and methods signify whether the attributes and methods are public or private. The attribute or method is considered private if there is a minus sign. This means that no other class can access the attribute or method; only methods in the class can inspect or change it.

If the attribute or method has a plus sign to the left, the attribute or method is public, and any class can inspect or modify it. For example, consider the following:

 -companyNumber:float +companyAge:int 

In this example, companyNumber is private, and only methods of its class can do anything with it. However, companyAge is public, and thus it is fair game for any class to access and modify it.

If no access designation is present in the code, the system considers the access to be the default, and no plus or minus is used:

 companyNumber:float companyAge:int 

Protected Access

In Java, the default type of access is protected. Protected access means that only classes in the package can access the attribute or method. A Java package is a collection of related classes that are intentionally grouped together by the developer.