-= Operator (Visual Basic)
Subtracts the value of an expression from the value of a variable or property and assigns the result to the variable or property.
variableorproperty -= expression
Required. Any numeric variable or property.
Required. Any numeric expression.
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.
-= operator first subtracts the value of the expression (on the right-hand side of the operator) from the value of the variable or property (on the left-hand side of the operator). The operator then assigns the result of that operation to the variable or property.
The - Operator (Visual Basic) 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.
The following example uses the
-= operator to subtract one
Integer variable from another and assign the result to the latter variable.
Dim var1 As Integer = 10
Dim var2 As Integer = 3
var1 -= var2
' The value of var1 is now 7.