ActionScript 2.0 Language Reference - Adobe Help and Support

Converts expression1 and expression2 to 32-bit integer values; you can call them V1 and
V2. Shifts all bits of the value of V1 to the left by V2 positions. Discards bits shifted off the
left end of V1 by this operation, and inserts zeros in the bit positions on the right that are
emptied. Shifting a value left by one position is the equivalent of multiplying it by 2.
Floating-point numbers are converted to integers by discarding any digits after the decimal
point. Positive integers are converted to an unsigned hexadecimal 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 hexadecimal 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 Player 5
Operands
expression1 : Number - A number or expression to be shifted left.
expression2 : Number - A number or expression that converts to an integer from 0 to 31.
Returns
Number - The result of the bitwise operation.
Example
In the following example, the integer 1 is shifted 10 bits to the left: x = 1