An object diagram illustrates specific instances of classes, as Figure A.4 shows.
In Figure A.4, note the following.
An object typically appears as a colon followed by the name of the class, all underlined, in a rectangle. For example, :Repetition indicates an object of the Repetition class.
A diagram can point out the name of a variable that references an object by prepending the name, as in good:Sequence.
A line between objects indicates that one object has a reference to another.
An object diagram can show the value of an instance ...