PHPCon Poland 2024


(PHP 5, PHP 7, PHP 8)

variant_subSubtracts the value of the right variant from the left variant value


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

Subtracts right from left.



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

Variant Subtraction Rules
If Then
Both expressions are of the string type Subtraction
One expression is a string type and the other a character Subtraction
One expression is numeric and the other is a string Subtraction.
Both expressions are numeric Subtraction
Either expression is NULL NULL is returned
Both expressions are empty Empty string is returned


Throws a com_exception on failure.

See Also

  • variant_add() - "Adds" two variant values together and returns the result

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