Java Reference
In-Depth Information
When used with boolean operands, | is the infrequently used Boolean OR
operator described earlier.
Bitwise XOR ( ^ )
This operator combines its two integer operands by performing a Boolean
XOR (exclusive OR) operation on their individual bits. The result has a bit set
if the corresponding bits in the two operands are different. If the correspondā
ing operand bits are both 1s or both 0s, the result bit is a 0. For example:
10 ^ 7 // 00001010 ^ 00000111 = => 00001101 or 13
When used with boolean operands, ^ is the seldom used Boolean XOR
operator.
Let shit ( << )
The << operator shifts the bits of the left operand left by the number of places
specified by the right operand. High-order bits of the left operand are lost, and
zero bits are shifted in from the right. Shifting an integer left by n places is
equivalent to multiplying that number by 2 n . For example:
10 << 1 // 00001010 << 1 = 00010100 = 20 = 10*2
7 << 3 // 00000111 << 3 = 00111000 = 56 = 7*8
- 1 << 2 // 0xFFFFFFFF << 2 = 0xFFFFFFFC = -4 = -1*4
If the left operand is a long , the right operand should be between 0 and 63.
Otherwise, the left operand is taken to be an int , and the right operand should
be between 0 and 31.
Signed right shit ( >> )
The >> operator shifts the bits of the left operand to the right by the number of
places specified by the right operand. The low-order bits of the left operand are
shifted away and are lost. The high-order bits shifted in are the same as the
original high-order bit of the left operand. In other words, if the left operand is
positive, 0s are shifted into the high-order bits. If the left operand is negative,
1s are shifted in instead. This technique is known as sign extension ; it is used to
preserve the sign of the left operand. For example:
10 >> 1 // 00001010 >> 1 = 00000101 = 5 = 10/2
27 >> 3 // 00011011 >> 3 = 00000011 = 3 = 27/8
- 50 >> 2 // 11001110 >> 2 = 11110011 = -13 != -50/4
If the left operand is positive and the right operand is n , the >> operator is the
same as integer division by 2 n .
Unsigned right shit ( >>> )
This operator is like the >> operator, except that it always shifts zeros into the
high-order bits of the result, regardless of the sign of the left-hand operand.
This technique is called zero extension ; it is appropriate when the left operand
is being treated as an unsigned value (despite the fact that Java integer types are
all signed). These are examples:
Search WWH ::

Custom Search