What does the ">>" symbol mean in Java?

Question

I see a line in some code I'm looking at and it says (12 >> 1) - 1). I print that value out and it comes out as a 5. If I change the 12 to 5, it comes out as a 1.

What is the ">>" symbol doing exactly?

yeah I just saw that when I wrote 12 out in binary. Thanks for the reply! — Bad Dub, May 02 '15 at 16:06
Second link on A Famous Web Search Engine for "java >> operator": [The official Java operators tutorial](https://docs.oracle.com/javase/tutorial/java/nutsandbolts/operators.html) — T.J. Crowder, May 02 '15 at 16:07

score 57 · Answer 1 · edited Jan 30 '20 at 22:38

>> is the signed right shift operator. It shifts a bit pattern to the right. The bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand.

When you shift right two bits, you drop the two least significant bits.

Let’s say, x = 00111011

So when you do, x >> 2, it results in x = 00001110

This is essentially the same thing as dividing a value by 4 or by 2 two times while dropping the fractional part.

So, below code will result in 4:

byte val = 100;
val = (byte) (val >> 2);
System.out.println(val);

Explaining your example:

The binary representation of 12 is: 1100
12 >> 1 is equivalent to 0110 which is 6 in decimal
so (12 >> 1) - 1) is equivalent to 6-1 that is 5

perhaps you meant result will be 25? 100 / 4 != 4;) – Eugene Troyanskii Jan 15 '19 at 15:12 — Eugene Troyanskii, Jan 15 '19 at 15:12

CSCH · Accepted Answer · 2015-05-02T16:12:51.627

36

12 is 1100 in binary. A right shift (>> is the bitwise right shift operator) by one bit produces

1100 -> 0110

which comes out to be 6.

Thus we have that,

6 - 1 = 5

edited May 02 '15 at 16:12

answered May 02 '15 at 16:08

CSCH

621
6
15

score 4 · Answer 3 · answered May 02 '15 at 16:13

See Bitwise and Bit Shift Operators

The Java programming language also provides operators that perform bitwise and bit shift operations on integral types. The signed left shift operator << shifts a bit pattern to the left, and the signed right shift operator >> shifts a bit pattern to the right. The bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand. The unsigned right shift operator >>> shifts a zero into the leftmost position, while the leftmost position after >> depends on sign extension.

(12 >> 1) - 1)

>> shifts binary 12(1100) 1 times to the right.
12 >> 1 == 6(110)

6 - 1 == 5

score 2 · Answer 4 · edited Jan 30 '20 at 22:33

2

It's a bit-shift operator. See here.

edited Jan 30 '20 at 22:33

Peter Mortensen

30,738
21
105
131

answered May 02 '15 at 16:06

pathfinderelite

3,047
1
27
30

score 2 · Answer 5 · edited Jan 30 '20 at 22:33

2

>> performs arithmetic right shift.

For example:

12 >> 1 = 6
-12 >> 1 = -6

edited Jan 30 '20 at 22:33

Peter Mortensen

30,738
21
105
131

answered May 02 '15 at 16:07

botismarius

2,977
2
30
29

score 1 · Answer 6 · edited Jan 30 '20 at 22:35

1

Binary right shift operator. The left operand's value is moved right by the number of bits specified by the right operand. For example, A >> 2 will give 15 which is 1111 in binary.

More information: Bitwise and Bit Shift Operators

edited Jan 30 '20 at 22:35

Peter Mortensen

30,738
21
105
131

answered May 02 '15 at 16:07

Cristiam Mercado

573
12
34

What does the ">>" symbol mean in Java?

6 Answers6

Linked