methods , deep look

Object Oriented Methods : Deeper Look Lecture Three
1
Experience has shown that the best way to develop and maintain a large
program is to construct it from small, simple pieces, or modules. This technique is
called divide and conquer. Methods, which we introduced in Last lectures, help you
modularize programs. Here , we study methods in more depth. We emphasize how
to declare and use methods to facilitate the design, implementation, operation and
maintenance of large programs.
Methods (called functions or procedures in some languages) help you
modularize a program by separating its tasks into self-contained units. You’ve
declared methods in every program you’ve written. The statements in the method
bodies are written only once, are hidden from other methods and can be reused from
several locations in a program. One motivation for modularizing a program into
methods is the divide-and-conquer approach, which makes program development
more manageable by constructing programs from small, simple pieces. Another is
software reusability sing existing methods as building blocks to create new
programs. Often, you can create programs mostly from standardized methods rather
than by building customized code. For example, in earlier programs, we did not
define how to read data from the keyboard Java provides these capabilities in the
methods of class Scanner. A third motivation is to avoid repeating code. Dividing a
program into meaningful methods makes the program easier to debug and maintain.
Static methods and Math Class:
We use various Math class methods here to present the concept of static
methods. Class Math provides a collection of methods that enable you to perform
common mathematical calculations. For example, you can calculate the square root
of 900.0 with the static method call.
Math.sqrt( 900.0 )
University of Babylon
Collage of Computer
Assistant Lecturer : Wadhah
R. Baiee
Exercise :
Build your own MyMath class with many
common mathematical methods without using
default Java Math class and its methods.
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