ShiftRotateRight

(twinBASIC) Rotates the bits of an integral value right by a given number of positions. The bits shifted out at the low end come back in at the high end.

Syntax: ShiftRotateRight( number, shiftamount )

number
required An expression of an integral type: Byte, Integer, Long, LongLong, LongPtr, Currency or Boolean. Any other type, a Variant included, is compile error TB5023, first argument must be a simple integral type.
shiftamount
required A numeric expression giving the number of bit positions to rotate. It is converted to a Long.

The result has the type of number. The rotation works on all the bits of that type: 8 for a Byte, 16 for an Integer or a Boolean, 32 for a Long, 64 for a LongLong or a Currency, and 32 or 64 for a LongPtr, as the build is 32-bit or 64-bit. A Currency is rotated as the 64-bit integer that stores it, which is its value multiplied by 10,000.

The rotation count is taken modulo the number of bits, so rotating a Long by 32 gives the value unchanged, and by 33 the same as by 1. A negative shiftamount rotates left. No value of shiftamount raises an error.

Unlike the >> operator, which discards the bits shifted out, ShiftRotateRight loses no bits, and it never copies the sign bit: &H12345678 >> 4 is &H1234567, and ShiftRotateRight(&H12345678, 4) is &H81234567.

With constant arguments, the call is evaluated when the code is compiled, so it can be used in a Const declaration, an Enum member’s value or a Case expression.

Note

ShiftRotateRight is a twinBASIC extension. VBA and VB6 have no function of this name: a call to it is the compile error Sub or Function not defined.

Example 

Dim Value As Long = &H12345678
Debug.Print Hex(ShiftRotateRight(Value, 4))     ' 81234567
Debug.Print Hex(ShiftRotateRight(Value, -4))    ' 23456781
Debug.Print Hex(Value >> 4)                     ' 1234567

See Also