COM 函数
PHP Manual

variant_mul

(PHP 5, PHP 7)

variant_mulMultiplies the values of the two variants

说明

mixed variant_mul ( mixed $left , mixed $right )

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

参见


COM 函数
PHP Manual