132
ActionScript language elements
>> bitwise right shift operator
expression1
>>
expression2
Converts
expression1
and
expression2
to 32-bit integers, and shifts all the bits in
expression1
to the right by the number of places specified by the integer that results from
the conversion of
expression2
. Bits that are shifted off the right end are discarded. To
preserve the sign of the original
expression
, the bits on the left are filled in with 0 if the
most significant bit (the bit farthest to the left) of
expression1
is 0, and filled in with 1 if the
most significant bit is 1. Shifting a value right by one position is the equivalent of dividing by
2 and discarding the remainder.
Floating-point numbers are converted to integers by discarding any digits after the decimal
point. Positive integers are converted to an unsigned hex value with a maximum value of
4294967295 or 0xFFFFFFFF; values larger than the maximum have their most significant
digits discarded when they are converted so the value is still 32-bit. Negative numbers are
converted to an unsigned hex value via the two's complement notation, with the minimum
being -2147483648 or 0x800000000; numbers less than the minimum are converted to two's
complement with greater precision and also have the most significant digits discarded.
The return value is interpreted as a two's complement number with sign, so the return value
will be an integer in the range -2147483648 to 2147483647.
Availability:
ActionScript 1.0; Flash Lite 2.0
Operands
expression1 :
Number
- A number or expression to be shifted right.
expression2 :
Number
- A number or expression that converts to an integer from 0 to 31.
Returns
Number
- The result of the bitwise operation.
Example
The following example converts 65535 to a 32-bit integer and shifts it 8 bits to the right:
var x:Number = 65535 >> 8;
trace(x); // outputs 255
The following example shows the result of the previous example:
var x:Number = 255;
This is because 65535 decimal equals 1111111111111111 binary (sixteen 1s),
1111111111111111 binary shifted right by 8 bits is 11111111 binary, and 11111111 binary
is 255 decimal. The most significant bit is 0 because the integers are 32-bit, so the fill bit is 0.
Summary of Contents for FLASHLITE2 ACTIONSCRIPT-LANGUAGE
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