Type conversion functions in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of converting string to double and back

What is the output of this MATLAB code?

MATLAB

x = '123.45';
y = str2double(x);
z = num2str(y);
disp(z);

A 123.45

B '123.45'

C Error: Conversion failed

D 12345

💡 Hint

str2double converts string to number, num2str converts number back to string.

str2double converts the string '123.45' to the numeric value 123.45. num2str converts the number back to the string '123.45'. disp prints the string without quotes.

❓ Predict Output

intermediate

Result of logical to double conversion

What is the output of this MATLAB code?

MATLAB

a = true;
b = double(a);
disp(b);

A true

B 1

C 0

D Error: Cannot convert logical to double

💡 Hint

Logical true converts to 1 as a double.

In MATLAB, logical true converts to double 1. disp prints the numeric value 1.

❓ Predict Output

advanced

Output of converting numeric array to char

What is the output of this MATLAB code?

MATLAB

nums = [65 66 67];
chars = char(nums);
disp(chars);

A ABC

B [65 66 67]

C Error: Cannot convert numeric array to char

D abc

💡 Hint

char converts numeric ASCII codes to characters.

65, 66, 67 are ASCII codes for 'A', 'B', 'C'. char converts them to the string 'ABC'.

❓ Predict Output

advanced

Result of converting cell array of strings to numeric array

What is the output of this MATLAB code?

MATLAB

c = {'1', '2', '3'};
n = str2double(c);
disp(n);

A {1, 2, 3}

B Error: Cannot convert cell array to numeric array

C [1 2 3]

D ["1" "2" "3"]

💡 Hint

str2double converts each string in the cell array to a number.

str2double converts each string element in the cell array to a numeric value, resulting in a numeric array [1 2 3].

❓ Predict Output

expert

Output of converting mixed numeric types to single precision

What is the output of this MATLAB code?

MATLAB

a = int16(1000);
b = double(a);
c = single(b);
disp(class(c));

A double

B Error: Invalid conversion

C int16

D single

💡 Hint

int16 to double to single changes the class accordingly.

int16 value 1000 converts to double 1000, then to single 1000. disp(class(c)) prints 'single'.