Find Number of Function Arguments

Use nargin and nargout to determine how many input or output arguments your function receives.

Support Variable Number of Inputs

Define a function that accepts a variable number of input arguments using varargin. The varargin argument is a cell array that contains the function inputs, where each input is in its own cell.

Support Variable Number of Outputs

Define a function that returns a variable number of output arguments using varargout. Output varargout is a cell array that contains the function outputs, where each output is in its own cell.

Validate Number of Function Arguments

Check if your custom function receives a valid number of input or output arguments. MATLAB^® performs some argument checks automatically. For other cases, you can use narginchk or nargoutchk.

Ignore Function Inputs

If your function accepts a predefined set of inputs, but does not use all the inputs, the tilde (~) operator to ignore them in your function definition.

Check Function Inputs with validateattributes

This example shows how to verify that the inputs to your function conform to a set of requirements using the validateattributes function.

Parse Function Inputs

Define required and optional inputs, assign defaults to optional inputs, and validate all inputs to a custom function using the Input Parser.