CODEWITHSUNDEEP
javabitwise-operatorsbitwise-or
kmanu
kmanu

Reputation: 44

Use of | in java

I came across a java code in which the constant has been defined in the following way

 static final char   FM = (char) (ConstantsSystem.DOUBLE_BYTE_SEP | 0xFE);

what is the use of | in this code?

Upvotes: 1

Views: 98

Answers (1)

Anderson Vieira
Anderson Vieira

Reputation: 9049

The | is the bitwise OR operator. It works as follows:

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

Internally, an integer is represented as a sequence of bits. So if you have, for example:

int x = 1 | 2;

This would be equivalent to:

int x = 0001 | 0010;
int x = 0011;
int x = 3;

Note I am using only 4 bits for clarity, but an int in Java is represented by 32 bits.

Specifically addressing your code, if we assume, for example, that the value of ConstantsSystem.DOUBLE_BYTE_SEP is 256:

static final char FM = (char) (ConstantsSystem.DOUBLE_BYTE_SEP | 0xFE);
static final char FM = (char) (256 | 254);
static final char FM = (char) (0000 0001 0000 0000 | 0000 0000 1111 1110);
static final char FM = (char) (0000 0001 1111 1110);
static final char FM = (char) (510);
static final char FM = 'Ǿ';

Also note that the way I wrote the binary numbers is not how you represent binaries in Java. For example:

0000 0000 1111 1110

would be really:

0b0000000011111110

Documentation: Bitwise and Bit Shift Operators

Upvotes: 8

Related Questions