Elmo HARmonica, HARSFEN0602 software manual Dummy variables, Count of output variables

HARSFEN0602ElmoHARmonicaSoftwareManual			PRELIMINARYDRAFT
	y1	= x1;	** Function body
	y2	= x2;
	if x2 > 0		** If block
	return		** return inside block is not the end of the
			function
	end		** End of if block
	y2	= y1 + y2 ;	** Some executable code
	return		** Function end

Before function call, it must be declared. It may be either function prototype or function definition.

For example,

13	function [int y1, int y2] = func	** Function prototype.
	(float x1, int x2) ;
	…
	function main()	** Function main definition
	int a, b;	** Local variable definition
	[a,b] = func(2.3, -9.0);	** Function call
	return	** Function main end
	…
	function [int y1, int y2] = func	** Function definition
	(float x1, int x2)
	…	** Function body
	return	** Function end

If any function declared without body, its call is illegal.

For example,

14	function [int y1, int y2] = func	** Function prototype.
	(float x1, int x2) ;
	…
	function main()	** Function main definition
	int a, b;	** Local variable definition
	[a,b] = func(2.3, -9.0);	** Function call
	return	** Function main end
	…

In this example function func has prototype, but has no body, so its call is illegal.

5.6.2Dummy variables

The input arguments and the output arguments of a function are called dummy variables. A true variable is substituted for the dummy variable when a function is called.

Example: In the example of the statistic function from the next chapter, variables mean and std are the dummy variables.

5.6.3Count of output variables

A function may return multiple values. In some cases, not all the outputs need be computed. A function can use the nargout keyword –to know how much of its results it actually needs to evaluate.

Number of outputs is the number of items in the left hand side expression during the function call. If its number exceeds the number of maximal defined output arguments of this function or the maximal admissible number of output arguments, it’s an error.

42