Operator -= (Subtract And Assign)

Subtracts and assigns a value to a variable

Syntax
	KeyPgDeclareDeclare KeyPgOperatorOperator -= ( KeyPgByrefByRef lhs KeyPgAsAs T1, KeyPgByrefByRef rhs KeyPgAsAs T2 )
	KeyPgDeclareDeclare KeyPgOperatorOperator -= ( KeyPgByrefByRef lhs KeyPgAsAs T KeyPgPtrPtr, KeyPgByrefByRef rhs KeyPgAsAs KeyPgInteger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 KeyPgOpSubtract- 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 
	KeyPgOperator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 CompilerOptlang-lang qb dialect, this operator cannot be overloaded.

Differences from QB
	* New to FreeBASIC

See also
	* KeyPgOpSubtractOperator - (Subtract)
	* CatPgMathMathematical Functions

