Description

Used to increment a variable by a specified amount.

Syntax

result += expression

The += operator syntax has these parts:

Part	Description
result	Any variable.
expression	Any expression.

Remarks

Using this operator is exactly the same as specifying:

result = result + expression

The underlying subtype of the expressions determines the behavior of the += operator in the following way:

If	Then
Both expressions are numeric or boolean	Add.
Both expressions are strings	Concatenate.
One expression is numeric and the other is a string	Concatenate.

For information on when a run-time error is generated by the += operator, please see the Arithmetic Operators table.