Lower 8-bits of integer

Posted on 2003-11-24
Last Modified: 2010-03-31
Given an integer of max length 16-bits how does one read the lower 8-bits, or is this not really a question.

I read that a java method converts the lower 8-bits of its integer param and converts it to the ASCII equiv.

Question by:robert_83
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 7
  • 2
LVL 35

Expert Comment

ID: 9810113
int lower = full & 0xFF ;
LVL 35

Expert Comment

ID: 9810114
char ch = (char)( theInt & 0xFF ) ;
LVL 35

Expert Comment

ID: 9810125
To get the 8 bits above that, you'd do:

char ch = (char)( ( theInt >> 8 ) & 0xFF ) ;
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

LVL 35

Expert Comment

ID: 9810127
these examples assume that "full" or "theInt" is you int variable :-)

Author Comment

ID: 9810299
Could you briefly explain the theory of suppose i supply 8000, how to get the lower 8-bits.

This question originated from using DataInputStream readChar, then output the char. No matter what character it read from the text file it always outputted '?'

LVL 35

Expert Comment

ID: 9810373
"&" does a bitwise AND on the integer value...

0xFF is 11111111 in binary, so say you have the number 345, in binary, that is:


so, if we AND it wil 0xFF:

101011001 (345) AND
011111111 (255 -- padded on the left with a zero)
001011001 (89)

Hope this explains it?

Let me know if you need more of an explanation...

LVL 35

Expert Comment

ID: 9810383
Ahhh...using your example:

1111101000000 (8000) AND
0000011111111 (255 -- 0xFF)
0000001000000 (64)

Author Comment

ID: 9811003
thanks for the reply, clear and concise.

I have a text file containing "r".

dis = DataInputStream(new FileInputStream(file));
char c = dis.readChar()
output = ?

Why does it output ?.

LVL 35

Accepted Solution

TimYates earned 50 total points
ID: 9811302
If it's a text file, use a Reader:

BufferedReader br = new BufferedReader( new FileReader( file ) ) ;
char c = (char) ;
System.out.println( c ) ;

should work...

if not, it is probably an encoding problem...

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

After being asked a question last year, I went into one of my moods where I did some research and code just for the fun and learning of it all.  Subsequently, from this journey, I put together this article on "Range Searching Using Visual Basic.NET …
Introduction This article is the second of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers the basic installation and configuration of the test automation tools used by…
Viewers learn about the third conditional statement “else if” and use it in an example program. Then additional information about conditional statements is provided, covering the topic thoroughly. Viewers learn about the third conditional statement …
This video teaches viewers about errors in exception handling.

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question