Anonymous functions in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of an anonymous function with vector input

What is the output of the following MATLAB code?

MATLAB

f = @(x) x.^2 + 2*x + 1;
result = f([1 2 3]);
disp(result);

A [4 9 16]

B [4 8 12]

C [4 9 15]

D [1 4 9]

💡 Hint

Remember that the operator .^ applies element-wise power to each element in the vector.

The anonymous function computes (x^2 + 2*x + 1) element-wise. For x=1: 1+2+1=4, for x=2: 4+4+1=9, for x=3: 9+6+1=16.

❓ Predict Output

intermediate

Output of nested anonymous functions

What is the output of this MATLAB code?

MATLAB

g = @(x) x + 1;
h = @(f, x) f(x) * 2;
result = h(g, 3);
disp(result);

A 6

B 7

C 8

D 9

💡 Hint

Evaluate the inner function g(3) first, then multiply by 2.

g(3) = 3 + 1 = 4. Then h calls g(3) and multiplies by 2, so 4 * 2 = 8.

🔧 Debug

advanced

Identify the error in anonymous function definition

Which option will cause an error when defining the anonymous function in MATLAB?

A f = @(x) x^2 + 3*x + 2;

B f = @(x) x.^2 + 3*x + 2;

C f = @(x) (x^2) + 3*x + 2;

D f = @(x) x**2 + 3*x + 2;

💡 Hint

Check the operator used for power in MATLAB.

MATLAB uses ^ for power, not **. Using ** causes a syntax error.

❓ Predict Output

advanced

Output of anonymous function with conditional expression

What is the output of this MATLAB code?

MATLAB

f = @(x) (x > 0) .* x + (x <= 0) .* 0;
result = f([-2 0 3]);
disp(result);

A [0 0 3]

B [-2 0 3]

C [0 0 0]

D [1 0 3]

💡 Hint

The function returns x if x is positive, otherwise 0.

For each element: if x>0, output x; else output 0. So -2 -> 0, 0 -> 0, 3 -> 3.

🧠 Conceptual

expert

Behavior of anonymous functions capturing variables

Consider the following MATLAB code. What is the value of y after running it?

MATLAB

a = 5;
f = @(x) x + a;
a = 10;
y = f(3);

A 8

B 13

C 3

D Error due to variable scope

💡 Hint

Anonymous functions use the current value of workspace variables at the time of execution.

The anonymous function looks up 'a' from the workspace when it is called. By then 'a' is 10, so f(3) = 3 + 10 = 13.