nargin, nargout
Number of function arguments
Syntax
nargin
nargin(fun)
nargout
nargout(fun)
Description
In the body of a function, nargin and nargout indicate how many input or output arguments, respectively, a user has supplied. Outside the body of a function, nargin and nargout indicate the number of input or output arguments, respectively, for a given function. The number of arguments is negative if the function has a variable number of arguments.
nargin returns the number of input arguments specified for a function.
nargin(fun) returns the number of declared inputs for the function fun. If the function has a variable number of input arguments, nargin returns a negative value. fun may be the name of a function, or the name of Function Handles that map to specific functions.
nargout returns the number of output arguments specified for a function.
nargout(fun) returns the number of declared outputs for the function fun. If the function has a variable number of output arguments, nargout returns a negative value. fun may be the name of a function, or the name of Function Handles that map to specific functions.
Examples
This example shows portions of the code for a function called myplot, which accepts an optional number of input and output arguments:
function [x0, y0] = myplot(x, y, npts, angle, subdiv)
% MYPLOT Plot a function.
% MYPLOT(x, y, npts, angle, subdiv)
% The first two input arguments are
% required; the other three have default values.
...
if nargin < 5, subdiv = 20; end
if nargin < 4, angle = 10; end
if nargin < 3, npts = 25; end
...
if nargout == 0
plot(x, y)
else
x0 = x;
y0 = y;
end
See Also
inputname, varargin, varargout, nargchk, nargoutchk