php man page for variant_add

VARIANT_ADD(3)								 1							    VARIANT_ADD(3)

variant_add - ";Adds" two variant values together and returns the result

SYNOPSIS
       mixed variant_add (mixed  $left, mixed  $right)

DESCRIPTION
	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
	      o $left
		- The left operand.

	      o $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(3) in PHP cor-
	      responds to VarAdd()  in the MSDN documentation.

RETURN VALUES
	Returns the result.

SEE ALSO
       variant_sub(3).

PHP Documentation Group 													    VARIANT_ADD(3)