String vs character array in MATLAB - Practice Questions

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of string concatenation vs character array concatenation

What is the output of the following MATLAB code?

MATLAB

str1 = "Hello";
str2 = "World";
char1 = ['Hello'];
char2 = ['World'];

result1 = str1 + " " + str2;
result2 = [char1 ' ' char2];
disp(result1)
disp(result2)

A

HelloWorld
Hello World

B

Hello World
HelloWorld

C

Hello World
Hello World

D

Error
Hello World

💡 Hint

Remember that strings use + for concatenation, while character arrays use square brackets [].

In MATLAB, strings (double quotes) concatenate with + operator, adding spaces if included. Character arrays concatenate by placing them inside square brackets []. Both produce the same visible output when displayed.

❓ Predict Output

intermediate

Length difference between string and character array

What will be the output of the following MATLAB code?

MATLAB

str = "MATLAB";
charArr = ['M' 'A' 'T' 'L' 'A' 'B'];
lenStr = strlength(str);
lenChar = length(charArr);
disp(lenStr)
disp(lenChar)

A

7
6

B

6
6

C

6
7

D

Error
6

💡 Hint

Check how strlength and length functions behave on strings and character arrays.

strlength returns the number of characters in a string. length returns the number of elements in an array. Both return 6 here.

🔧 Debug

advanced

Identify the error when mixing string and character array

What error does the following MATLAB code produce?

MATLAB

str = "Data";
charArr = ['S' 'c' 'i' 'e' 'n' 'c' 'e'];
result = str + charArr;

A Error: Undefined operator '+' for input arguments of type 'string' and 'char'.

B DataScience

C Data Science

D Error: Matrix dimensions must agree.

💡 Hint

Consider the types of variables and what + operator supports.

MATLAB does not allow + operator between a string and a character array. This causes an undefined operator error.

🧠 Conceptual

advanced

Difference in indexing between string and character array

Consider the following MATLAB code:

str = "Hello";
charArr = ['H' 'e' 'l' 'l' 'o'];

char1 = str(2);
char2 = charArr(2);

What are the values of char1 and char2?

A char1 is a string "e"; char2 is a character 'e'

B char1 is a character 'e'; char2 is a string "e"

C char1 is a string "el"; char2 is a character 'e'

D char1 is a character 'e'; char2 is a character 'l'

💡 Hint

Remember that indexing a string returns a string scalar, indexing a character array returns a char.

Indexing a string returns a string scalar (still double quotes). Indexing a character array returns a single character (single quotes).

❓ Predict Output

expert

Behavior of strcmp with string and character array

What is the output of this MATLAB code?

MATLAB

str = "Test";
charArr = ['T' 'e' 's' 't'];
result = strcmp(str, charArr);
disp(result)

A Error: Inputs must be character arrays or cell arrays of character vectors.

B 0

C Error: Undefined function 'strcmp' for input arguments of type 'string' and 'char'.

D 1

💡 Hint

Check if strcmp supports comparing string and character array.

strcmp converts string inputs to character arrays internally and compares them correctly, returning 1 for equality.