Input and output arguments 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 [3 6]

B [4 6]

C [4 3]

D [6 4]

💡 Hint

Remember the function returns two outputs: a = x+1 and b = x*2.

The function example adds 1 to input x for output a, and multiplies x by 2 for output b. For x=3, a=4 and b=6, so the output is [4 6].

❓ Predict Output

intermediate

Value of output argument after function call

What is the value of variable y after running this code?

MATLAB

function y = squarePlusOne(x)
    y = x^2 + 1;
end

result = squarePlusOne(4);
y = result;

A 5

B 16

C 17

D 8

💡 Hint

Calculate 4 squared plus 1.

4 squared is 16, plus 1 equals 17, so y is 17.

🔧 Debug

advanced

Identify the error in function output assignment

What error will this MATLAB code produce when run?

MATLAB

function [a, b] = faultyFunc(x)
    a = x + 2;
end

[a_out, b_out] = faultyFunc(5);

A Error: Variable 'b' is undefined.

B Error: Function syntax error.

C No error, outputs are [7, 0].

D Error: Not enough output arguments.

💡 Hint

Check if the function returns all requested outputs.

The function defines two outputs but only assigns one. Calling with two outputs causes 'Not enough output arguments' error.

📝 Syntax

advanced

Correct syntax for multiple output arguments

Which option shows the correct syntax to define a function with two output arguments in MATLAB?

A function [out1, out2] = myFunc(input)

B function (out1, out2) = myFunc(input)

C function out1 out2 = myFunc(input)

D function out1, out2 = myFunc(input)

💡 Hint

Look for square brackets around output variables.

MATLAB requires square brackets around multiple outputs in function definition: function [out1, out2] = myFunc(input)

🚀 Application

expert

Number of output arguments returned by a function call

Given the function below, how many output arguments does the call [x, y] = computeValues(2) return?

MATLAB

function [a, b, c] = computeValues(n)
    a = n;
    b = n^2;
    c = n^3;
end

[x, y] = computeValues(2);

A 2

B 3

C 1

D 0

💡 Hint

The number of outputs depends on the left side of the call.

Even though the function returns 3 outputs, the call requests only 2 outputs, so only 2 are returned.