Method Naming Conventions

The Date-Time API offers a rich set of methods within a rich set of classes. The method names are made consistent between classes wherever possible. For example, many of the classes offer a now method that captures the date or time values of the current moment that are relevant to that class. There are from methods that allow conversion from one class to another.

There is also standardization regarding the method name prefixes. Because most of the classes in the Date-Time API are immutable, the API does not include set methods. (After its creation, the value of an immutable object cannot be changed. The immutable equivalent of a set method is with.) The following table lists the commonly used prefixes:

Prefix Method Type Use
of static factory Creates an instance where the factory is primarily validating the input parameters, not converting them.
from static factory Converts the input parameters to an instance of the target class, which may involve losing information from the input.
parse static factory Parses the input string to produce an instance of the target class.
format instance Uses the specified formatter to format the values in the temporal object to produce a string.
get instance Returns a part of the state of the target object.
is instance Queries the state of the target object.
with instance Returns a copy of the target object with one element changed; this is the immutable equivalent to a set method on a JavaBean.
plus instance Returns a copy of the target object with an amount of time added.
minus instance Returns a copy of the target object with an amount of time subtracted.
to instance Converts this object to another type.
at instance Combines this object with another.