CODEWITHSUNDEEP
java
user1932898
user1932898

Reputation:

Java | operator with integers;

I do program with Java for about one year, but still found something I do not know. How does:

new Font(FontFamily.TIMES_ROMAN, 12, 1 | 4);

How | does work with integers?

Thank You

P.S. I googled a lot.

Upvotes: 5

Views: 482

Answers (3)

AllTooSir
AllTooSir

Reputation: 49412

It is a bitwise OR operator , operates on one or more bit patterns or binary numerals at the level of their individual bits.

The bitwise ^ operator performs a bitwise exclusive OR operation.

OR bitwise operation will return 1 if any of operand is 1 and zero only if both operands are zeros.

You can get the complete description in the JLS 15.22.1.

 0|0 = 0
 0|1 = 1
 1|0 = 1
 1|1 = 1

Hence in your case , the operands are 1 and 4 . Converting them into binary (only the last 4 digits) will be 0100 and 0001 respectively. Apply the | now bit by bit :

0 1 0 0
0 0 0 1
---------
0 1 0 1 = (5 in base 10)

Upvotes: 7

Joni
Joni

Reputation: 111349

The | operator calculates the "bit-wise OR" of its operands. To understand it you have to convert the operands to binary: it produces a "0" bit if the bit is not set in either numbers, and a "1" bit if it is set in either.

With your numbers, the result of 4|1 is 5 because:

  4 = 100
  1 = 001
4|1 = 101 = 5

The bit-wise OR operator is related to the "bit-wise AND" operator &, which produces a "0" if the bit is not set in one of the numbers and a "1" bit if it is set in both.

Since these operators work on the bit-wise representation of their arguments they can be hard to understand when you're used to working on decimal (base 10) numbers. The following relation holds, which makes it easy to derive the result of one when you have the other:

a + b = (a|b) + (a&b)

Upvotes: 11

ameed
ameed

Reputation: 1170

The | is called bitwise OR. This works by:

  1. Converting each number to binary
  2. Doing boolean OR (||) on each digit in a matching position (0 is false, 1 is true)
  3. Converting the result back to decimal

For example,

   100 | 4
OR 001 | 1
-------+--
   101 | 5

The properties on the Font constructor are designed so in binary, exactly one digit is a 1. By ORing these numbers, you get the digits turned on that represent the options that are ORed.

Upvotes: 1

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