Logical operators (&, |, ~) in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of logical AND and OR operations

What is the output of the following MATLAB code?

MATLAB

A = [1 0 1];
B = [0 0 1];
C = A & B;
D = A | B;
disp(C);
disp(D);

A

[0 0 0]
[1 1 1]

B

[0 0 1]
[1 0 1]

C

[1 0 1]
[1 0 1]

D

[1 1 1]
[0 0 0]

💡 Hint

Remember that & returns true only if both elements are true, | returns true if at least one is true.

The logical AND (&) compares each element: 1&0=0, 0&0=0, 1&1=1. The logical OR (|) compares each element: 1|0=1, 0|0=0, 1|1=1.

❓ Predict Output

intermediate

Output of logical NOT operation

What does the following MATLAB code display?

MATLAB

X = [true false true false];
Y = ~X;
disp(Y);

A [false true false true]

B [true false true false]

C [1 0 1 0]

D [0 1 0 1]

💡 Hint

The ~ operator flips true to false and false to true.

The ~ operator negates each logical element: true becomes false, false becomes true.

🔧 Debug

advanced

Identify the error in logical expression

What error does this MATLAB code produce?

MATLAB

A = [1 0 1];
B = [0 1];
C = A & B;

A Dimension mismatch error

B Syntax error

C No error, outputs [0 0 1]

D Index exceeds matrix dimensions

💡 Hint

Logical operators require arrays to be the same size or compatible.

The arrays A and B have different lengths, so element-wise logical AND (&) cannot be performed, causing a dimension mismatch error.

❓ Predict Output

advanced

Result of combined logical operations

What is the output of this MATLAB code?

MATLAB

A = [1 0 1 0];
B = [0 1 1 0];
C = ~(A & B) | (A & ~B);
disp(C);

A [0 0 0 0]

B [0 1 1 0]

C [1 1 0 1]

D [1 1 1 1]

💡 Hint

Break down the expression step by step: compute A & B, then negate, then compute A & ~B, then OR the results.

A & B = [0 0 1 0], ~(A & B) = [1 1 0 1], A & ~B = [1 0 0 0], OR gives [1 1 0 1] | [1 0 0 0] = [1 1 0 1]. But option C is [1 1 1 1], so re-check: Actually, A & ~B = [1 0 0 0], so final OR is [1 1 0 1]. So option C matches. Correct answer is B.

🧠 Conceptual

expert

Understanding precedence of logical operators

Given the expression in MATLAB: true | false & false, what is the result?

A true

B false

C Error due to ambiguous operators

D Depends on variable types

💡 Hint

Remember that & has higher precedence than | in MATLAB.

The expression is evaluated as true | (false & false). false & false is false, so true | false is true.