Passing Parameters to Functions

A better way to convey information from one function to another is to pass parameters to the called function. Design the function so it expects to receive a number of values. Remember the Degrees->Radians function? This function is passed a parameter named numberOfDegrees:

(defun Degrees->Radians (numberOfDegrees) 
(* pi (/ numberOfDegrees 180.0)))

When you call the function, it expects you to pass it a number. The number within Degrees->Radians is declared as the parameter named numberOfDegrees. For example:

(degrees->radians 90)
1.5708

In this case, the number 90 is assigned to the parameter numberOfDegrees.

You can also pass a variable to a function. For example, you might have a variable called aDegreeValue that contains the number 90. The following commands set aDegreeValue and pass the variable to Degrees->Radians:

(setq aDegreeValue 90)
90

(degrees->radians aDegreeValue)
1.5708