There is another category of functions which can be used apart from those listed in Section 10.7. These are called, in Java/object-oriented parlance, "instance methods" and represent functions that can be executed on an object.
It is possible to invoke any of its public
instance methods on any object
(though not on primitive values - numeric and boolean ones).
The syntax is that you place a "." followed by the method invocation
after the object you want to invoke the method on,
hence NAME.substring(3) instead of substring(NAME,3).
If you know what you're doing, feel free to go ahead and do this.
However, most of the instance methods you're likely to want to use
have equivalents in the normal functions listed in the previous section,
so unless you're a Java programmer or feeling adventurous,
you may be best off ignoring this feature.