Library classes

745 views
713 views

Published on

Library classes

Published in: Education, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
745
On SlideShare
0
From Embeds
0
Number of Embeds
70
Actions
Shares
0
Downloads
5
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Library classes

  1. 1. Library classes
  2. 2. Class creation• User defined (if the user creates)• Library classes (Readily available with the system)
  3. 3. LIST OF LIBRARY CLASSES• Java.io• Java.lang• Java.awt• Java.util• Java.applet• Java.net• Java.math
  4. 4. Input operations in java• System.in.read();• In.readLine();
  5. 5. Output operations in java• System.out.print();• System.out.println();
  6. 6. Types of streamsInput stream related to keyboard• System.inOutput stream related to VDU• System.out• System.errThese streams are available in java.io
  7. 7. Categories of stream• Character related Referred as reader stream and writer stream (for character encoding)• Byte related Any data in terms of byte can be inputted
  8. 8. Exception & Exception handling• An unexpected situation which occurs due to improper use of input resources during the execution of the program• The process of eliminating unexpected errors during runtime
  9. 9. TRY and CATCH Try contains block of statements to perform An error will be trapped in try block Hence try is an error trapper Catch will be informed about the error and catch the errors
  10. 10. Throws Keyword Applied with the function signature Throws IOException If error occurs it will report to the error handler
  11. 11. Wrapper classes• It is a member of java library• It wraps the primitive data type in an object
  12. 12. Need of Wrapper class• To store primitive values in objects as well as in conversion from string to primitive types• Ex :• String x = “12”;• int c =Integer.parseInt(x);
  13. 13. Static data members• Instant variables which is global in the class and used commonly by all the objects of that class
  14. 14. Static member methods• Method which uses only static data members or static instant variables
  15. 15. Packages in java• It is a group of class which can be imported to a program to use implicit facilities• It can be included by using import keyword• A package may be defined by the user and is termed as user defined packages

×