How to Return Multiple Values in MATLAB Functions

In MATLAB, you can return multiple values from a function by listing them as multiple output arguments in square brackets, like [out1, out2] = functionName(inputs). Inside the function, assign values to each output variable in order. This allows you to get several results from one function call.

Syntax

The basic syntax to return multiple values from a MATLAB function is:

[output1, output2, ..., outputN] = functionName(input1, input2, ...)

Here:

• output1, output2, ..., outputN are the variables that will receive the returned values.
• functionName is the name of your function.
• input1, input2, ... are the inputs to the function.

Inside the function, you assign values to each output variable in the order they are declared.

matlab

function [a, b] = exampleFunction(x)
    a = x + 1;
    b = x * 2;
end

Example

This example shows a function that returns two values: the square and the cube of the input number.

matlab

function [square, cube] = powers(num)
    square = num^2;
    cube = num^3;
end

% Call the function
[sq, cb] = powers(3);

% Display the results
fprintf('Square: %d\n', sq);
fprintf('Cube: %d\n', cb);

Output

Square: 9
Cube: 27

Common Pitfalls

Common mistakes when returning multiple values in MATLAB include:

• Not using square brackets [] around multiple output variables when calling the function.
• Assigning fewer output variables than the function returns, which can cause errors or missing values.
• Not matching the order of outputs in the function definition and the call.

Always use square brackets to capture multiple outputs and ensure the number of outputs matches.

matlab

function [x, y] = wrongExample(a)
    x = a + 10;
    y = a - 5;
end

% Wrong way (missing brackets):
[x, y] = wrongExample(7); % Correct way

% Right way:
[x, y] = wrongExample(7);

Quick Reference

Concept	Description	Example
Multiple outputs	Use square brackets to list outputs	[out1, out2] = func(inputs)
Assign outputs	Assign values inside function in order	out1 = val1; out2 = val2;
Call function	Use brackets to capture multiple outputs	[a, b] = func(x);
Output order	Order of outputs matters	Match function and call order

Key Takeaways

Use square brackets to return and capture multiple values in MATLAB functions.

Assign each output variable inside the function in the order declared.

Match the number and order of outputs between function definition and call.

Always use brackets when calling functions that return multiple values.

Avoid missing or extra output variables to prevent errors.