Function handles in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple function handle call

What is the output of this MATLAB code?

MATLAB

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

A 15

B 9

C 7

D 11

💡 Hint

Calculate 2 squared plus 3 times 2 plus 1.

The function computes x^2 + 3*x + 1. For x=2, 2^2=4, 3*2=6, sum is 4+6+1=11.

❓ Predict Output

intermediate

Function handle with multiple inputs

What is the output of this MATLAB code?

MATLAB

g = @(x,y) x*y + y^2;
val = g(3,4);
disp(val);

A 28

B 19

C 25

D 16

💡 Hint

Calculate 3*4 + 4^2.

g(3,4) = 3*4 + 4^2 = 12 + 16 = 28.

🔧 Debug

advanced

Identify the error in function handle usage

What error does this MATLAB code produce?

MATLAB

h = @(x) x(2) + 5;
result = h(3);
disp(result);

A Undefined function or variable 'x'.

B Index exceeds matrix dimensions.

C Syntax error: missing operator.

D No error, output is 8.

💡 Hint

Check how x is used inside the function handle.

The function tries to access the second element of x, but x is a scalar (3), so indexing fails.

🧠 Conceptual

advanced

Function handle behavior with variable scope

Consider this MATLAB code snippet. What is the output?

MATLAB

a = 10;
f = @(x) x + a;
a = 20;
disp(f(5));

A 15

B Error: Undefined variable 'a'.

C 25

D 5

💡 Hint

Anonymous functions in MATLAB capture variables by value at the time of creation.

When the function handle is created, a=10 is captured. Changing a to 20 afterward does not affect the function. Thus, f(5) = 5 + 10 = 15.

❓ Predict Output

expert

Output of nested function handles with array input

What is the output of this MATLAB code?

MATLAB

f1 = @(x) x.^2;
f2 = @(g, y) g(y) + 1;
arr = [1, 2, 3];
result = f2(f1, arr);
disp(result);

A [1 4 9]

B [2 4 6]

C [2 5 10]

D Error: Matrix dimensions must agree.

💡 Hint

Apply f1 to each element of arr, then add 1 to each result.

f1 squares each element: [1 4 9]. Adding 1 gives [2 5 10].