logical-and()

Boolean AND operation. This function returns "true" if a and b and all further (non-empty) parameters are "true", "false" otherwise.

Parameters

Note: There is a difference between parameters a, b and parameters c, d, e. The logical operator AND with a variable number of parameters needs a rule for unused parameters. Since an AND operation needs at least two parameters, a and b need to have a Boolean value, so they are not optional. If a or b have no assigned values, they will get the value "false". For the optional parameters c to e, an unassigned value is interpreted as the parameter not being used. Unused parameters have to be interpreted as "true" for the AND operation to return the logically correct result, meaning parameters c to e will be interpreted as "true" if they have no assigned value. So make sure that all parameters that should be used have a valid Boolean value ("true" or "false").

Examples