How Strings Work Differently Across Languages in DSA Python - Debugging & Practice

Challenge - 5 Problems

❓ Predict Output

intermediate

String Immutability in Python

What is the output of this Python code snippet?

DSA Python

s = "hello"
s[0] = 'H'
print(s)

A SyntaxError

B hello

C Hello

D TypeError

💡 Hint

Strings in Python cannot be changed after creation.

Strings in Python are immutable. Trying to assign a new character to an index causes a TypeError.

❓ Predict Output

intermediate

String Concatenation Performance

What is the output of this Python code?

DSA Python

result = ''
for i in range(3):
    result += str(i)
print(result)

A ['0', '1', '2']

B 0 1 2

C 012

D Error

💡 Hint

The loop appends string versions of numbers to result.

The loop concatenates '0', '1', and '2' to the empty string, resulting in '012'.

❓ Predict Output

advanced

String Interning Behavior

What is the output of this Python code snippet?

DSA Python

a = 'hello'
b = 'hello'
print(a is b)

A True

B False

C Error

D None

💡 Hint

Python may reuse the same string object for identical literals.

Python interns short strings, so 'a' and 'b' point to the same object, making 'a is b' True.

❓ Predict Output

advanced

Unicode String Length

What is the output of this Python code?

DSA Python

s = 'naïve'
print(len(s))

A 5

B 6

C 4

D Error

💡 Hint

Python 3 strings are Unicode and count characters, not bytes.

The string 'naïve' has 5 characters including the 'ï' which counts as one character.

❓ Predict Output

expert

Mutable vs Immutable String-like Types

What is the output of this Python code?

DSA Python

from array import array
s = 'abc'
a = array('u', s)
a[0] = 'z'
print(''.join(a))

A ValueError

B zbc

C abc

D TypeError

💡 Hint

array of type 'u' supports mutable Unicode characters.

The array of Unicode characters is mutable, so changing index 0 to 'z' works and prints 'zbc'.