Variable arguments (varargin, varargout) in MATLAB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a function that accepts a variable number of input arguments.

MATLAB

function varargout = myFunction([1])
% This function accepts variable input arguments
n = nargin;
varargout = cell(1, n);

Drag options to blanks, or click blank then click option'

Avarargin

Bvarargout

Cinput

Dargs

Attempts:

3 left

💡 Hint

Common Mistakes

Using varargout instead of varargin for inputs

Using a regular variable name instead of varargin

The special input variable varargin allows a function to accept any number of input arguments.

2fill in blank

medium

Complete the code to access the number of input arguments inside the function.

MATLAB

function output = countInputs(varargin)
numArgs = [1];
output = numArgs;

Drag options to blanks, or click blank then click option'

Avarargin

Blength(varargin)

Cnargout

Dnargin

Attempts:

3 left

💡 Hint

Common Mistakes

Using nargout which counts output arguments

Using length(varargin) which works but nargin is preferred

nargin returns the number of input arguments passed to the function.

3fill in blank

hard

Fix the error in the function to correctly return variable output arguments.

MATLAB

function varargout = exampleFunc(varargin)
for k = 1:[1]
    varargout{k} = varargin{k}^2;
end

Drag options to blanks, or click blank then click option'

Anargout

Bnargin

Clength(varargin)

Dnumel(varargout)

Attempts:

3 left

💡 Hint

Common Mistakes

Using nargin which counts inputs instead of outputs

Using length(varargin) which counts inputs, not outputs

nargout gives the number of output arguments expected, which is needed to assign outputs correctly.

4fill in blank

hard

Fill both blanks to create a function that sums all input arguments and returns the sum and count.

MATLAB

function [total, count] = sumInputs([1])
total = 0;
for i = 1:[2]
    total = total + varargin{i};
end
count = nargin;

Drag options to blanks, or click blank then click option'

Avarargin

Bnargin

Clength(varargin)

Dvarargout

Attempts:

3 left

💡 Hint

Common Mistakes

Using nargout instead of length(varargin) for loop count

Using varargout instead of varargin for inputs

varargin is used to accept variable inputs, and length(varargin) gives the number of inputs to loop through.

5fill in blank

hard

Fill all three blanks to create a function that returns the first input squared, the number of inputs, and the number of outputs.

MATLAB

function [out1, out2, out3] = multiOutput([1])
out1 = varargin{1}^2;
out2 = [2];
out3 = [3];

Drag options to blanks, or click blank then click option'

Avarargin

Bnargin

Cnargout

Dlength(varargin)

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up nargin and nargout

Using length(varargin) instead of nargin

varargin is used for inputs, nargin gives the number of inputs, and nargout gives the number of outputs.