Databases
StackOverflow2013
Postsdbo
POHow are integers internally represented at a bit level in Java?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow are integers internally represented at a bit level in Java?
    primarykey
    data
    text
    <p>I am trying to understand how Java stores integer internally. I know all java primitive integers are signed, (except short?). That means one less bit available in a byte for the number.</p> <p>My question is, are all integers (positive and negative) stored as two's complement or are only negative numbers in two's complement?</p> <p>I see that the specs says <code>x bit two's complement number</code>. But I often get confused.</p> <p>For instance:</p> <pre><code> int x = 15; // Stored as binary as is? 00000000 00000000 00000000 00001111? int y = -22; // Stored as two complemented value? 11111111 11111111 11111111 11101010 </code></pre> <p><strong>Edit</strong></p> <p>To be clear, <code>x = 15</code> </p> <pre><code> In binary as is: `00000000 00000000 00000000 00001111' Two's complement: `11111111 11111111 11111111 11110001` </code></pre> <p>So if your answer is <code>all</code> numbers are stored as two's complement then:</p> <pre><code> int x = 15; // 11111111 11111111 11111111 11110001 int y = -22 // 11111111 11111111 11111111 11101010 </code></pre> <p>The confusion here again is the sign says, both are negative numbers. May be I am misreading / misunderstanding it?</p> <p><strong>Edit</strong> Not sure my question is confusing. Forced to isolate the question:</p> <p><strong>My question precisely: Are positive numbers stored in <code>binary as is</code> while negative numbers are stored as <code>two's complement</code>?</strong></p> <p>Some said all are stored in two's complement and one answer says only negative numbers are stored as two's complement.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USArtB
    1. USKevin Rave
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow are integers internally represented at a bit level in Java?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow are integers internally represented at a bit level in Java?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POHow are integers internally represented at a bit level in Java?
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO-ve numbers ????????
      singulars
      1. POHow are integers internally represented at a bit level in Java?
      1. USCoffee
    2. COTwo's complement necessarily means that positive numbers are represented by the actual bit values of that number... at least as I understand it. EDIT: Also, two's compliment means one less bit in the total number of bytes in the primitive, not one less bit PER byte.
      singulars
      1. POHow are integers internally represented at a bit level in Java?
      1. USLJ2
    3. COyour assumption is right: positive and negative numbers are two's complement, and your `x` and `y` are correct.
      singulars
      1. POHow are integers internally represented at a bit level in Java?
      1. USjlordo
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload