Multiplies the values of the two variants

说明

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

Multiplies left by right.

参数

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

Boolean values are converted to -1 for FALSE and 0 for TRUE.

Note:
对于所有变量运算函数，本函数的参数可以是 PHP 内置的类型（整数，字符串，浮点数，布尔型或者 NULL），或者是一个 COM，VARIANT 或者 DOTNET 类的实例。PHP 内置类型将会使用和构造VARIANT类相同的规则转换成变量。COM 和 DOTNET 对象的值将会取其默认属性并被当成变量值使用。

变量运算函数是同名函数在 COM 库中的外包；有关此类函数的更多信息参见 MSDN 库。PHP 函数命名有少许区别，例如 PHP 中的 variant_add() 对应于 MSDN 文档中的 VarAdd()。

返回值

**Variant Multiplication Rules**
If	Then
Both expressions are of the string, date, character, boolean type	Multiplication
One expression is a string type and the other a character	Multiplication
One expression is numeric and the other is a string	Multiplication
Both expressions are numeric	Multiplication
Either expression is NULL	NULL is returned
Both expressions are empty	Empty string is returned

错误／异常

Throws a com_exception on failure.

参见

variant_div() - Returns the result from dividing two variants
variant_idiv() - Converts variants to integers and then returns the result from dividing them