ROL

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

• _ROR, _SHL, _SHR
• _BYTE, INTEGER
• LONG, _INTEGER64

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