_ROL

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The _ROL function is used to rotate the bits of a numerical value to the left. A rotation (or circular shift) is an operation similar to shift (_SHL and _SHR) except that the bits that fall off at one end are put back to the other end.


Syntax

result = _ROL(numericalVariable, numericalValue)


Parameters

  • numericalVariable is the variable to shift the bits of and can be of the following types: _BYTE, INTEGER, LONG, or _INTEGER64.
  • Integer values can be signed or _UNSIGNED.
  • numericalValue is the number of places to rotate the bits.
  • While 0 is a valid value it will have no affect on the variable being rotated.


Description

  • In left rotation, the bits that fall off at left end are put back at right end.
  • The type of variable used to store the results should match the type of the variable being shifted.


Availability

  • QB64-PE v3.1.0 and up


Examples

OPTION _EXPLICIT

DIM a AS _UNSIGNED _BYTE
DIM b AS _UNSIGNED INTEGER
DIM c AS _UNSIGNED LONG
DIM d AS _UNSIGNED _INTEGER64

a = &B11110000
b = &B1111111100000000
c = &B11111111111111110000000000000000
d = &B1111111111111111111111111111111100000000000000000000000000000000

DO
    a = _ROL(a, 1)
    b = _ROL(b, 1)
    c = _ROL(c, 1)
    d = _ROL(d, 1)

    LOCATE 1, 1: PRINT RIGHT$(STRING$(8, "0") + _BIN$(a), 8);
    LOCATE 2, 1: PRINT RIGHT$(STRING$(16, "0") + _BIN$(b), 16);
    LOCATE 3, 1: PRINT RIGHT$(STRING$(32, "0") + _BIN$(c), 32);
    LOCATE 4, 1: PRINT RIGHT$(STRING$(64, "0") + _BIN$(d), 64);

    _LIMIT 15
LOOP WHILE _KEYHIT <> 27


See also



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