PHP: "Adds" two variant values together and returns the result

Description

mixed variant_add ( mixed $left , mixed $right )

Adds left to right using the following rules (taken from the MSDN library), which correspond to those of Visual Basic:
Variant Addition Rules

If Then

Both expressions are of the string type Concatenation

One expression is a string type and the other a character Addition

One expression is numeric and the other is a string Addition

Both expressions are numeric Addition

Either expression is NULL NULL is returned

Both expressions are empty Integer subtype is returned

Parameters

left: The left operand.
right: The right operand.

Note: As with all the variant arithmetic functions, the parameters for this function can be either a PHP native type (integer, string, floating point, boolean or NULL), or an instance of a COM, VARIANT or DOTNET class. PHP native types will be converted to variants using the same rules as found in the constructor for the VARIANT class. COM and DOTNET objects will have the value of their default property taken and used as the variant value.
The variant arithmetic functions are wrappers around the similarly named functions in the COM library; for more information on these functions, consult the MSDN library. The PHP functions are named slightly differently; for example variant_add() in PHP corresponds to VarAdd() in the MSDN documentation.

Return Values

Returns the result.

variant_add

Description

Parameters

Return Values

See Also