Answer Posted / hrindows@gmail.com
A class in Java is a blueprint that includes all your data. A class contains fields (variables) and methods to describe the behavior of an object. Let’s have a look at the syntax of a class.
class Abc {
member variables // class body
methods}
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
What is user defined exception in Java?
Is 0 a real number?
Why map is used in java?
What is java util concurrentmodificationexception?
What is the difference between variable & constant?
Suppose if we have variable ' I ' in run method, if I can create one or more thread each thread will occupy a separate copy or same variable will be shared?
List two java ide’s?
Which api is provided by java for operations on set of objects?
Explain which of the following methods releases the lock when yield(), join(),sleep(),wait(),notify(), notifyall() methods are executed?
What is import java util arraylist?
What is jit compiler in java?
Can keyword be used as identifier?
Explain the difference between abstraction and encapsulation.
What is blank final variable?
3.2 Consider the following class: public class Point { protected int x, y; public Point(int xx, int yy) { x = xx; y = yy; } public Point() { this(0, 0); } public int getx() { return x; } public int gety() { return y; } public String toString() { return "("+x+", "+y+")"; } } Say you wanted to define a rectangle class that stored its top left corner and its height and width as fields. 3.2.1 Why would it be wrong to make Rectangle inherit from Point (where in fact it would inherit the x and y coordinates for its top left corner and you could just add the height and width as additional fields)? (1) 8 Now consider the following skeleton of the Rectangle class: public class Rectangle { private Point topLeft; private int height, width; public Rectangle(Point tl, int h, int w) { topLeft = tl; height = h; width = w; } public Rectangle() { this(new Point(), 0, 0); } // methods come here } 3.2.2 Explain the no-argument constructor of the Rectangle class given above. 3.2.3 Write methods for the Rectangle class to do the following: • a toString() method that returns a string of the format "top left = (x, y); height = h; width = w " where x, y, h and w are the appropriate integer values. • an above() method that tests whether one rectangle is completely above another (i.e. all y values of the one rectangle are greater than all y values of the other). For example, with the following declarations Rectangle r1 = new Rectangle(); Rectangle r2 = new Rectangle(new Point(2,2), 1, 4); the expression r2.above(r1) should give true, and r2.above (r2) should give false. (You can assume that the height of a rectangle is never negative.) (2) (5)