Multiple outputs in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a function with multiple outputs

What is the output of the following MATLAB code?

MATLAB

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

[a_out, b_out] = example(3);
disp([a_out, b_out]);

A [6 4]

B [3 6]

C [4 6]

D [4 3]

💡 Hint

Remember the function adds 1 to x for the first output and multiplies x by 2 for the second output.

The function returns two outputs: a = x + 1 = 4, and b = x * 2 = 6. So the displayed array is [4 6].

❓ Predict Output

intermediate

Using only one output from a function with multiple outputs

What will be the output of this MATLAB code?

MATLAB

function [a, b] = example(x)
    a = x^2;
    b = x^3;
end

result = example(2);
disp(result);

A [4 8]

B 4

C [2 4]

D Error: Too many output arguments.

💡 Hint

When calling a function with multiple outputs but only one variable, MATLAB returns the first output.

Only the first output 'a' is assigned to 'result', which is 2^2 = 4.

🔧 Debug

advanced

Identify the error in multiple output assignment

What error will this MATLAB code produce?

MATLAB

function [x, y] = calc()
    x = 5;
    y = 10;
end

[a, b, c] = calc();

A Error: Undefined function or variable 'c'.

B Error: Not enough output arguments.

C No error, a=5, b=10, c=0

D Error: Too many output arguments.

💡 Hint

The function returns only two outputs but you are trying to assign three.

The function returns two outputs but the caller expects three, causing a 'Too many output arguments' error.

❓ Predict Output

advanced

Output of nested function calls with multiple outputs

What is the output of this MATLAB code?

MATLAB

function [sumVal, prodVal] = compute(a, b)
    sumVal = a + b;
    prodVal = a * b;
end

[x, y] = compute(2, 3);
[z, w] = compute(x, y);
disp([z, w]);

A [11 30]

B [5 6]

C [5 15]

D [6 7]

💡 Hint

First compute(2,3) returns sum=5 and product=6. Then compute(5,6) returns sum=11 and product=30.

First call: [x, y] = compute(2, 3) returns x=5, y=6. Second call: [z, w] = compute(5, 6) returns z=11, w=30. disp([z, w]) displays [11 30].

❓ Predict Output

expert

Multiple outputs with conditional assignment

What is the output of this MATLAB code?

MATLAB

function [a, b] = conditionalOutputs(x)
    if x > 0
        a = x;
        b = x^2;
    else
        a = -x;
        b = -x^2;
    end
end

[p, q] = conditionalOutputs(-3);
disp([p, q]);

A [3 -9]

B [-3 -9]

C [3 9]

D [-3 9]

💡 Hint

Check the else branch for negative input values.

Since x = -3 (less than 0), a = -(-3) = 3, b = -((-3)^2) = -9, so output is [3 -9].