Each function declared in the field of global variables and functions has a group of own variables and functions which are accessible to this function and to its local functions only.

 

input variables

 

In the field of local variables and functions of each global function there is an element of the input variables, in which variables representing the function's input parameters may be positioned. These variables appear when using the functions in a program, too. By setting the input variables values input parameters may be passed over to the function. If the input variable value is not set when calling the function, its default value will remain preset. During the function execution the input variables may be treated like normal local variables.

 

output variable

 

Another element existing in the field of the local variables and functions is the output variable. This element can include one variable representing the function's output value. During the function execution the output variable may be treated like a normal local variable. After ending the function the value of the output variable will be passed over as an output value. When calling the function as a command the output value will be ignored.