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fun [2019/12/09 21:25] – [Functions with no parameters] neilsfun [2020/08/07 09:02] (current) – correct FUNC to FUN thraka
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 The ''FUN ... ENDFUN'' directives are used for defining a user function. Functions are similar to procedures with the exception that: The ''FUN ... ENDFUN'' directives are used for defining a user function. Functions are similar to procedures with the exception that:
  
-  * They **must** return a value +  * They **must** return a value. 
-  * They can be called from within an expression+  * They can be called from within an expression. 
 + 
 +The name of the function and the name of a parameter **can't** start with a command or directive name. For example, you can't define a function named ''repeatnumber'' as ''REPEAT'' is a command. Likewise, you can't name a parameter ''funparameter1'' as ''FUN'' is a directive.
  
 ===== Defining functions ===== ===== Defining functions =====
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 If you want a routine that does not return a value, use [[procedures|]] instead. If you want a routine that does not return a value, use [[procedures|]] instead.
  
-==== Functions with no parameters ====+==== Parameterless functions ====
  
 You can omit the parameter list, but bear in mind that you still have to write the empty parentheses: You can omit the parameter list, but bear in mind that you still have to write the empty parentheses:
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 You can call a function from within an expression by using the function name, sigil and the argument list in parentheses, for example: You can call a function from within an expression by using the function name, sigil and the argument list in parentheses, for example:
  
-  let x! = my_function!(a, b!)+  let x! = my_function!(a, b!) * 2
      
 Note that in the example above ''my_function!'' is a function that returns a byte and accepts an integer and a byte as arguments. Note that in the example above ''my_function!'' is a function that returns a byte and accepts an integer and a byte as arguments.
  
 Important note: you must pass exactly the same amount of parameters and the parameter types must match those in the function definition. Important note: you must pass exactly the same amount of parameters and the parameter types must match those in the function definition.
 +
 +===== Recursion =====
 +
 +While procedures do support direct recursion, functions don't.