PCEP-30-02 3.4 working with strings.txt

PCEP-30-02 3.4 working with strings in Python, including constructing strings, indexing, slicing, immutability, escaping, quotes and apostrophes inside strings, multi-line strings, and basic string functions and methods:

1. Which of the following is a valid way to create a string in Python?
   A) str = 'Hello'
   B) str = "Hello"
   C) str = '''Hello'''
   D) All of the above

2. What is the output of the following code?
   ```python
   s = "Python"
   print(s[1])
   ```
   A) P
   B) y
   C) t
   D) h

3. What is string slicing?
   A) Removing characters from a string
   B) Adding characters to a string
   C) Extracting a portion of a string
   D) Replacing characters in a string

4. Which of the following is true about strings in Python?
   A) Strings are mutable
   B) Strings are immutable
   C) Strings can be changed in-place
   D) None of the above

5. How do you escape a single quote in a string that's enclosed in single quotes?
   A) \'
   B) "'"
   C) \\'
   D) Both A and B

6. What is the output of this code?
   ```python
   print("He said, \"Hello!\"")
   ```
   A) He said, "Hello!"
   B) He said, \"Hello!\"
   C) "He said, "Hello!""
   D) SyntaxError

7. How can you create a multi-line string?
   A) Using triple quotes (''' or """)
   B) Using \n in a regular string
   C) Using the + operator to concatenate strings
   D) All of the above

8. What is the output of this code?
   ```python
   s = "Hello\nWorld"
   print(len(s))
   ```
   A) 10
   B) 11
   C) 12
   D) Error

9. Which method converts a string to uppercase?
   A) s.upper()
   B) s.capitalize()
   C) s.top()
   D) s.uppercase()

10. What is the output of this code?
    ```python
    s = "  Hello, World!  "
    print(s.strip())
    ```
    A) "Hello, World!"
    B) "Hello,World!"
    C) "  Hello, World!  "
    D) "Hello, World!  "

11. How do you check if a string starts with a specific substring?
    A) s.startswith("sub")
    B) s.begins("sub")
    C) s.start("sub")
    D) "sub" in s[0]

12. What is the output of this code?
    ```python
    s = "Python"
    print(s[-2])
    ```
    A) P
    B) n
    C) o
    D) t

13. Which method splits a string into a list of substrings?
    A) s.split()
    B) s.divide()
    C) s.separate()
    D) s.break()

14. What is the output of this code?
    ```python
    s = "Hello" + " " + "World"
    print(s)
    ```
    A) HelloWorld
    B) Hello World
    C) "Hello World"
    D) Error

15. How can you find the index of a substring in a string?
    A) s.find("sub")
    B) s.index("sub")
    C) s.search("sub")
    D) Both A and B

16. What is the output of this code?
    ```python
    s = "Python"
    print(s[1:4])
    ```
    A) Pyt
    B) yth
    C) ytho
    D) ython

17. Which method replaces occurrences of a substring in a string?
    A) s.replace("old", "new")
    B) s.swap("old", "new")
    C) s.change("old", "new")
    D) s.substitute("old", "new")

18. What is the output of this code?
    ```python
    s = "Hello"
    print(s * 3)
    ```
    A) HelloHelloHello
    B) Hello3
    C) Error
    D) None of the above

19. How do you convert a string to lowercase?
    A) s.lower()
    B) s.lowercase()
    C) s.down()
    D) s.tolower()

20. What is the output of this code?
    ```python
    s = "Python Programming"
    print(s.count("P"))
    ```
    A) 1
    B) 2
    C) 3
    D) 0

21. Which of the following is true about string formatting in Python?
    A) It can be done using the % operator
    B) It can be done using the .format() method
    C) It can be done using f-strings (in Python 3.6+)
    D) All of the above

22. What is the output of this code?
    ```python
    s = "Hello\tWorld"
    print(len(s))
    ```
    A) 10
    B) 11
    C) 12
    D) Error

23. How can you check if a string contains only digits?
    A) s.isdigit()
    B) s.isnumeric()
    C) s.isdecimal()
    D) All of the above

24. What is the output of this code?
    ```python
    s = "Python"
    print(s[::-1])
    ```
    A) Python
    B) nohtyP
    C) Pytho
    D) Error

25. Which method joins elements of an iterable into a string?
    A) "".join(iterable)
    B) string.concat(iterable)
    C) string.merge(iterable)
    D) "".combine(iterable)

Answers:
1. D, 2. B, 3. C, 4. B, 5. D, 6. A, 7. D, 8. B, 9. A, 10. A, 11. A, 12. C, 13. A, 14. B, 15. D, 16. B, 17. A, 18. A, 19. A, 20. B, 21. D, 22. B, 23. D, 24. B, 25. A