Function definition syntax in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple function call

What is the output of this MATLAB code when calling result = addTwoNumbers(3, 5); disp(result);?

MATLAB

function sum = addTwoNumbers(a, b)
    sum = a + b;
end

A 8

B 35

C Error: Undefined function or variable 'addTwoNumbers'.

D 0

💡 Hint

Remember that the function adds the two input numbers.

The function addTwoNumbers takes two inputs and returns their sum. Calling it with 3 and 5 returns 8.

❓ Predict Output

intermediate

Output of a function with multiple outputs

What is the output of this MATLAB code snippet?
[minVal, maxVal] = findMinMax([4, 7, 1, 9]); disp([minVal, maxVal]);

MATLAB

function [minVal, maxVal] = findMinMax(arr)
    minVal = min(arr);
    maxVal = max(arr);
end

A Error: Too many output arguments.

B [4 7]

C [9 1]

D [1 9]

💡 Hint

The function returns the smallest and largest numbers in the array.

The function returns the minimum and maximum values of the input array. For [4,7,1,9], min is 1 and max is 9.

❓ Predict Output

advanced

Output of a nested function call

What is the output of this MATLAB code?
result = outerFunction(4); disp(result);

MATLAB

function out = outerFunction(x)
    function y = innerFunction(z)
        y = z^2;
    end
    out = innerFunction(x) + 1;
end

A 17

B 16

C Error: Nested functions are not allowed.

D 5

💡 Hint

The inner function squares the input, then 1 is added.

The inner function squares 4 to get 16, then outerFunction adds 1, resulting in 17.

❓ Predict Output

advanced

Output of a function with default argument behavior

What is the output of this MATLAB code?
disp(greet()); disp(greet('Alice'));

MATLAB

function message = greet(name)
    if nargin == 0
        name = 'Guest';
    end
    message = ['Hello, ', name, '!'];
end

A Hello, !<br>Hello, Alice!

B Hello, Guest!<br>Hello, Alice!

C Error: Not enough input arguments.

D Hello, Guest!<br>Hello, Guest!

💡 Hint

Check how the function handles missing input arguments.

If no input is given, the function sets name to 'Guest'. Otherwise, it uses the provided name.

❓ Predict Output

expert

Output of a recursive function

What is the output of this MATLAB code?
disp(factorialRecursive(4));

MATLAB

function f = factorialRecursive(n)
    if n == 0
        f = 1;
    else
        f = n * factorialRecursive(n - 1);
    end
end

A 1

B 10

C 24

D Error: Maximum recursion limit exceeded.

💡 Hint

Recall how factorial is calculated recursively.

Factorial of 4 is 4*3*2*1 = 24. The function calls itself until n=0, then multiplies back up.