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varargin

Variable-length input argument list

Syntax

Description

example

varargin is an input variable in a function definition statement that enables the function to accept any number of input arguments. Specify varargin by using lowercase characters. After any explicitly declared inputs, include varargin as the last input argument .

When the function executes, varargin is a 1-by-N cell array, where N is the number of inputs that the function receives after the explicitly declared inputs. If the function receives no inputs after the explicitly declared inputs, then varargin is an empty cell array.

Examples

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Define a function in a file named acceptVariableNumInputs.m that accepts a variable number of inputs and displays the values of each input.

type acceptVariableNumInputs
function acceptVariableNumInputs(varargin)
    disp("Number of input arguments: " + nargin)
    celldisp(varargin)
end

Call the function with several inputs.

acceptVariableNumInputs(ones(3),'some text',pi)
Number of input arguments: 3
 
varargin{1} =
 
     1     1     1
     1     1     1
     1     1     1

 
 
varargin{2} =
 
some text
 
 
varargin{3} =
 
    3.1416

 

Define a function in a file named definedAndVariableNumInputs.m that expects two inputs and accepts an additional number of inputs.

type definedAndVariableNumInputs
function definedAndVariableNumInputs(X,Y,varargin)
    disp("Total number of input arguments: " + nargin)
    
    formatSpec = "Size of varargin cell array: %dx%d";
    str = compose(formatSpec,size(varargin));
    disp(str)

end

Call the function with several inputs.

definedAndVariableNumInputs(7,pi,rand(4),datetime('now'),'hello')
Total number of input arguments: 5
Size of varargin cell array: 1x3

Call the function with two inputs. varargin is an empty cell array.

definedAndVariableNumInputs(13,42)
Total number of input arguments: 2
Size of varargin cell array: 0x0

Define a function in a file named variableNumInputAndOutput.m that accepts a variable number of inputs and outputs.

type variableNumInputAndOutput
function varargout = variableNumInputAndOutput(varargin)
    disp(['Number of provided inputs: ' num2str(length(varargin))])
    disp(['Number of requested outputs: ' num2str(nargout)])
    
    for k = 1:nargout
        varargout{k} = k;
    end
end

Call the function with two inputs and three outputs.

[d,g,p] = variableNumInputAndOutput(6,'Nexus')
Number of provided inputs: 2
Number of requested outputs: 3
d = 1
g = 2
p = 3

Call the function again with no inputs or outputs.

variableNumInputAndOutput
Number of provided inputs: 0
Number of requested outputs: 0

Extended Capabilities

Version History

Introduced before R2006a

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