SIMPOL Documentation

To define a function the keyword function is placed at the beginning of the line and outside the body of any other function. That is followed by at least one space and then the name of the function. Following the name is an opening parenthesis, the parameter list and then the closing parenthesis. The parameter list may be empty. If it is not, then the parameters are listed starting with their type and then the name of the parameter. A default value can also be assigned to a parameter by placing an equals sign after the parameter. The entire syntax diagram would look like: function <name>([<parameter type> <parameter name>[=<value>],…]). The return value of the function is placed on the last line of the function following the end function statement. This can be a variable, an expression, or even the entire function body (assuming it is a single statement). A function does not need to return a value.

To call a function it is sufficient to place the name of the function followed by the open parenthesis, the argument list, and the close parenthesis in the program code. If the function returns a value that can be assigned to a variable or used within an equation. Even if a function returns a value that value can be ignored if the programmer so chooses. The following is an example of the definition and calling of a function:

function main()
end function hello("world")

function hello(string s)
  string t

  t = "hello " + s
end function t