CascadiaPHP 2024


(PHP 5, PHP 7, PHP 8)

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


variant_add(mixed $left, mixed $right): variant

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



The left operand.


The right operand.


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.


Throws a com_exception on failure.

See Also

  • variant_sub() - Subtracts the value of the right variant from the left variant value

add a note

User Contributed Notes

There are no user contributed notes for this page.
To Top