Define the type casting?, JAVA Programming

Assignment Help:

 

Type casting defines treating a variable of one type as though it is another type.

When up casting primitives as given below from left to right, automatic conversion happens. But if you derive from right to left, explicit casting or down casting is needed. Casting in Java is safer and easier than in C or other languages that allow arbitrary casting. Java only lets casts happen when they build sense, such as a cast between a float and an int. However you can't cast between a String and an int.

Byte, short, int, long, float, and double

int i = 5;

long j = i;         //Right. Implicit casting or up casting

byte b1 = i;      //Wrong casting. Compile time error "Type Mismatch".

byte b2 = (byte) i ;       //Right. Explicit casting or Down casting is required.

When it needs to object references you may always cast from a subclass to a superclass because a subclass object is also a superclass instance. You may cast an object implicitly to a super class type. If that were not the case polymorphism couldn't be possible.

 

 

 

2281_Untitled.png

 

You can cast down the hierarchy as well but you have to explicitly write the cast and the object must be a legitimate instance of the class you are casting to. The ClassCastException is given to indicate that code has tried to cast an object to a subclass of which it is not an instance of that class. If you are using J2SE 5.0 then "generics" will remove the need for casting otherwise you may deal with the problem of incorrect casting in two ways:

1.      Use the exception handling process to catch ClassCastException.

2.      Use the instance of statement to protect against incorrect casting.

 


Related Discussions:- Define the type casting?

Explain jsp technology?, Java Server Page is a standard Java extension that...

Java Server Page is a standard Java extension that is described on top of the servlet Extensions. The goal of JSP is the simplified formation and management of dynamic Web pages. J

Rest client, Modify both of the above clients (to write separate clients) t...

Modify both of the above clients (to write separate clients) to extract the exchange rate from a live web service that performs currency conversion. You can choose a Java or a .NET

Explain the concept of multi-threaded- java, Explain the concept of Multi-T...

Explain the concept of Multi-Threaded- JAVA Java has a concept of concurrency wired right in to the language itself. This works out more cleanly than languages where concur

How can we include images in a web page using html and java, How can we inc...

How can we include images in a web page using HTML and Java script?2011 Images in HTML It is quite straight forward to include gif and jpg images in an HTML webpage using the

Write a program calculates the resistance of group resistors, The formula f...

The formula for resistors linked in parallel is a little more complex. Given two resistors along with resistances R1 and R2 linked in parallel the equivalent resistance is given th

Hotel online booking system, who can helps me with pseudocode with that top...

who can helps me with pseudocode with that topic above mencioned

Logic circuit, Design a logic circuit to convert Gray code to Binary code a...

Design a logic circuit to convert Gray code to Binary code and draw the logic circuit.

What can you do with an exception once you''ve caught it, What can you do w...

What can you do with an exception once you've caught it? 1. Fix the difficulty and try again. 2. Do anything else instead. 3. Exit the application along with System.exit() 4

I need social mobile application, Project Description: I'm using a php s...

Project Description: I'm using a php script called phpfox on my site its work as social network . So I need is to use this script as CMS for my application. What users wil

What do you mean by auto wiring, The Spring container is able to autowire r...

The Spring container is able to autowire relationships among collaborating beans. This means that it is possible to automatically let Spring resolve collaborators (other beans) for

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd