Operator -= (Subtract And Assign)

Subtracts and assigns a value to a variable

Syntax
   Declare Operator -= ( ByRef lhs As T1, ByRef rhs As T2 )
   Declare Operator -= ( ByRef lhs As T Ptr, ByRef rhs As Integer )

Usage
   lhs -= rhs

Parameters
   lhs
      The variable to assign to.
   T1
      Any numeric type.
   rhs
      The value to subtract from lhs.
   T2
      Any numeric type.
   T
      Any data type.

Description
   This operator subtracts and assigns a value to a variable. It is 
   functionally equivalent to:
      lhs = lhs - rhs

   For numeric types, the right-hand side expression (rhs) will be 
   converted to the left-hand side type (T1).

   This operator can be overloaded for user-defined types as a member 
   Operator using the appropriate syntax.

   Note: Similarly to the operator '=[>]' (assign), the alternative symbol 
   '-=>' can be also used.

Example
   Dim n As Double
   n = 6
   n -= 2.2
   Print n
   Sleep

Output:

   3.8

Dialect Differences
   * In the -lang qb dialect, this operator cannot be overloaded.

Differences from QB
   * New to FreeBASIC

See also
   * Operator - (Subtract)
   * Mathematical Functions

