Relational expressions in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of chained relational expressions

What is the output of this MATLAB code snippet?

MATLAB

a = 5;
b = 10;
c = 15;
result = (a < b) & (b < c);
disp(result);

A [1 1]

B 0

C Error: Undefined function or variable 'result'

D 1

💡 Hint

Recall that relational expressions return logical 1 (true) or 0 (false).

Both conditions (a < b) and (b < c) are true, so the logical AND (&) returns 1.

❓ Predict Output

intermediate

Relational expression with arrays

What is the output of this MATLAB code?

MATLAB

x = [2, 4, 6];
y = [3, 4, 5];
result = x >= y;
disp(result);

A [0 1 1]

B [1 1 1]

C [0 0 0]

D Error: Matrix dimensions must agree.

💡 Hint

Relational operators compare elements element-wise in arrays of the same size.

Comparing element-wise: 2>=3 is false (0), 4>=4 is true (1), 6>=5 is true (1).

❓ Predict Output

advanced

Result of mixing relational and logical operators

What does this MATLAB code display?

MATLAB

a = 7;
b = 5;
c = 7;
result = (a == c) | (b > a);
disp(result);

A [1 0]

B 0

C 1

D Error: Undefined function or variable 'result'

💡 Hint

The OR operator (|) returns true if either condition is true.

a == c is true (7 == 7), b > a is false (5 > 7). True OR false is true (1).

❓ Predict Output

advanced

Relational expression with mixed data types

What is the output of this MATLAB code?

MATLAB

x = 3;
y = '3';
result = (x == y);
disp(result);

A 0

B 1

C Error: Conversion to double from char is not possible.

D Error: Undefined function or variable 'result'

💡 Hint

MATLAB compares numeric and char types differently in relational expressions.

Numeric 3 is not equal to char '3', so the result is 0 (false).

❓ Predict Output

expert

Logical indexing with relational expressions

What is the output of this MATLAB code?

MATLAB

A = [10, 20, 30, 40, 50];
idx = A > 25;
result = A(idx);
disp(result);

A [25 30 40 50]

B [30 40 50]

C [10 20 25]

D Error: Index exceeds matrix dimensions.

💡 Hint

Logical indexing selects elements where the condition is true.

Elements greater than 25 are 30, 40, and 50, so result is [30 40 50].