Lecture 2

Question 1

What is casting

Answer 1

Casting is a mechanism of converting the value of an object or primitive type into another type.

Question 2

Describe java.lang

Answer 2

Classes that apply to the language itself, which includes the Object class, the String class, and the System class. It also contains the special classes for the primitive types (Integer, Character, Float, and so on).

Question 3

Describe java.util

Answer 3

Utility classes, such as Date, as well as simple collection classes, such as Vector and Hashtable.

Question 4

Describe java.io

Answer 4

java.io: Input and output classes for writing to and reading from streams (such as standard input and output) and for handling files.

Question 5

Describe java.net

Answer 5

java.net: Classes for networking support, including Socket and URL (a class to represent references to documents on the World Wide Web).

Question 6

Describe java.awt

Answer 6

(the Abstract Window Toolkit): Classes to implement a graphical user interface, including classes for Window, Menu, Button, Font, CheckBox, and so on.

This package also includes classes for processing images (the java.awt.Image package).

Question 7

Describe java.applet

Answer 7

java.applet: Classes to implement Java applets, including the Applet class itself, as well as the AudioClip class

Question 8

How to declare Arrays in Java

Answer 8

String[] difficultWords;
int[] temps;
String Records[][];

Question 9

How to create an array object

Answer 9

String[] difficultWords = new String[10];
String Records[][] = new String[10][80];
int[] temps=new int[5];

Question 10

What is a block statement

Answer 10

A block statement is a group of other statements surrounded by braces ({}).