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>>= Operator (Visual Basic)

  • Стаття

Performs an arithmetic right shift on the value of a variable or property and assigns the result back to the variable or property.

Syntax

variableorproperty >>= amount

Parts

variableorproperty
Required. Variable or property of an integral type (SByte, Byte, Short, UShort, Integer, UInteger, Long, or ULong).

amount
Required. Numeric expression of a data type that widens to Integer.

Remarks

The element on the left side of the >>= operator can be a simple scalar variable, a property, or an element of an array. The variable or property cannot be ReadOnly.

The >>= operator first performs an arithmetic right shift on the value of the variable or property. The operator then assigns the result of that operation back to the variable or property.

Arithmetic shifts are not circular, which means the bits shifted off one end of the result are not reintroduced at the other end. In an arithmetic right shift, the bits shifted beyond the rightmost bit position are discarded, and the leftmost bit is propagated into the bit positions vacated at the left. This means that if variableorproperty has a negative value, the vacated positions are set to one. If variableorproperty is positive, or if its data type is an unsigned type, the vacated positions are set to zero.

Overloading

The >> Operator can be overloaded, which means that a class or structure can redefine its behavior when an operand has the type of that class or structure. Overloading the >> operator affects the behavior of the >>= operator. If your code uses >>= on a class or structure that overloads >>, be sure you understand its redefined behavior. For more information, see Operator Procedures.

Example

The following example uses the >>= operator to shift the bit pattern of an Integer variable right by the specified amount and assign the result to the variable.

Dim var As Integer = 10
Dim shift As Integer = 2
var >>= shift
' The value of var is now 2 (two bits were lost off the right end).

See also