Answer Posted / qim2010

Java’s “new” operator is used to load the class statically.

class MyClass {
public static void main(String args[]) {
Car c = new Car();
}
}

Class.forName (String className); is used for dynamic class
loading. The string className can be supplied dynamically at
run time. Once the class is dynamically loaded the following
method returns an instance of the loaded class. It’s just
like creating a class object with no arguments.

class.newInstance (); //A non-static method, which creates
an instance of a
//class (i.e. creates an object).

Can you use this() and super() both in a constructor?

1038

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How do I find and replace in word?

1028

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What’s the difference between constructors and other methods?

1051

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List some oops concepts in java?

1093

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State two differences between C and Java.

1395

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What is equlas() and hashcode() contract in java? Where does it used?

1201

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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)

3040

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Explain with example the concept of constant variable in java.

1265

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How to do encapsulation in java?

1106

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What is a null point?

1157

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What is the difference between a local variable and an instance variable?

1181

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How do you implement singleton class?

1040

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What is a substitution variable?

1080

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What does function identity () do?

1025

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What do you mean by Function Overloading in java?

1226

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