Author Me Date 2006/5/30
My notes on Java
TipsConventions- class names begin with a capital letter
- constants are all CAPS (final means no changes/compiler check)
Default values- numeric types = zero
- char = '\u000'
- class references or references to arrays = null
A class file contains object definitions and methods: class | ---- Variables | ---- Methods - static variables are shared across the class
- instance variables are for each instance of the object
- public static void main() is the first executed object
modifiers = public, static, final, abstract, native, private, protected, synchronized types are value_type = void, integer, double, string, array, etc. [Note: I'm not sure if it's KIOVI editor or this module that causes the extra spacing for this code to go away upon submission, but it's annoying.]
/** * This is a special doc comment. * The javadoc program can yank these to create online * documentation (notice the ** at the start) */
/* * This is a standard set of comments */
ClassName varname = new ClassName(); // how to define a new classed variable modifier class ClassName { static var = null; vartype varname = null;
//method definition (return_type can be any - void returns nothing) //static allows to get to the method even if the values are null modifiers type methodName ( [type arg1], [type arg2], ..., [type argn]) {
//Executable code here return return_value; //or return; for voids } }
class Sphere { static final double PI = 3.141592638; // Class variable that has a fixed value static int count = 0; // Class variable to count objects
// Instance variables double radius; // Radius of a sphere double xCenter; // 3D coordinates double yCenter; // of the center double zCenter; // of a sphere
// Static method to report the number of objects created static int getCount() { return count; // Return current object count }
// Instance method to calculate volume double volume() { return 4.0/3.0*PI*radius*radius*radius; }
// Instance method to change the radius // Change the instance variable to the argument value void changeRadius(double radius) { this.radius = radius; }
// Plus the rest of the class definition... }
Threads and ConversationsSome excellent info...
|