Multiple outputs in MATLAB - Step-by-Step Execution

Concept Flow - Multiple outputs

Call function with multiple outputs

↓

Function runs code

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Assign values to output variables

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Return outputs to caller

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Caller receives multiple outputs

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Use outputs separately

This flow shows how a MATLAB function can return multiple outputs, which the caller receives and uses separately.

Execution Sample

MATLAB

function [sumVal, diffVal] = addAndSubtract(a, b)
    sumVal = a + b;
    diffVal = a - b;
end

[x, y] = addAndSubtract(5, 3);

This code defines a function that returns two outputs: sum and difference of two inputs, then calls it to get both results.

Execution Table

Step	Action	Variables	Output Variables Assigned	Result
1	Call addAndSubtract(5, 3)	a=5, b=3	None yet	Function starts
2	Calculate sumVal = a + b	a=5, b=3	sumVal=8	sumVal assigned 8
3	Calculate diffVal = a - b	a=5, b=3	diffVal=2	diffVal assigned 2
4	Return outputs to caller	sumVal=8, diffVal=2	x=8, y=2	Outputs assigned to x and y
5	Use outputs x and y	x=8, y=2	None	x=8, y=2 ready for use

💡 Function ends after returning both outputs to caller

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
a	undefined	5	5	5	5
b	undefined	3	3	3	3
sumVal	undefined	8	8	8	8
diffVal	undefined	undefined	2	2	2
x	undefined	undefined	undefined	8	8
y	undefined	undefined	undefined	2	2

Key Moments - 3 Insights

Why do we use square brackets [ ] when calling the function?

Square brackets tell MATLAB to expect multiple outputs. Without them, only the first output is returned (see execution_table step 4).

What happens if we ask for fewer outputs than the function provides?

MATLAB returns only the requested outputs. For example, if only one output is requested, only sumVal is returned (not shown here but implied by step 4).

Can we ignore some outputs when calling the function?

Yes, you can use ~ to ignore outputs you don't need, but the function still computes them internally (not shown in table but common practice).

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the value of diffVal?

A 2

B 3

C 8

D 5

💡 Hint

Check the 'Output Variables Assigned' column at step 3 in execution_table.

At which step are the outputs assigned to variables x and y in the caller?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look for when 'Outputs assigned to x and y' happens in execution_table.

If we call the function without square brackets, what will happen?

A An error occurs

B Both outputs are assigned to x

C Only the first output is returned

D All outputs are ignored

💡 Hint

Recall key_moments about output assignment and square brackets usage.

Concept Snapshot

Multiple outputs in MATLAB:
- Use [out1, out2, ...] = functionName(inputs)
- Function defines outputs in square brackets
- Caller receives outputs in order
- Use ~ to ignore outputs
- Without brackets, only first output returned

Full Transcript

This visual trace shows how MATLAB functions can return multiple outputs. The function addAndSubtract takes two inputs and returns two outputs: their sum and difference. The execution table walks through each step: calling the function, calculating outputs, and assigning them back to variables x and y in the caller. The variable tracker shows how each variable changes after each step. Key moments clarify why square brackets are needed to receive multiple outputs and what happens if fewer outputs are requested. The quiz tests understanding of output values and assignment steps. The snapshot summarizes the syntax and behavior for quick reference.