Question : W3Schools Var-Op-C 24

1. Variable Naming

2name = "Alex"

Why is this variable name invalid in Python?

2. Variable Naming Rule

user-name = "John"

What rule of variable naming is being violated here?

3. Case Sensitivity

age = 20
Age = 30

Are age and Age the same variable? Why or why not?

4. Reserved Words

class = "Science"

Why will this line cause an error?

5. Data Type Identification

x = 7.0

What is the data type of x, and how can you tell?

6. Type Conversion Issue

int("42.5")

Why does this cause an error, even though "42.5" looks like a number?

7. Input Always a String

value = input("Enter a number: ")

Why is the type of value a string even if the user types a number?

8. Input Conversion Error

n = int(input("Enter age: "))

What happens if the user enters "ten"? Why?

9. Division vs Floor Division

print(10 / 3)
print(10 // 3)

Why do these two lines produce different results?

10. Modulus Operator Usage

print(17 % 5)

What does the % operator compute here?

11. Exponent Operator

print(2 ** 3)

What does the ** operator do in this expression?

12. Comparison vs Assignment

a = 10
print(a == 10)

What is the difference between = and == in this example?

13. Indentation Requirement

if x > 10:
print("Greater")

Why will this code produce an indentation error?

14. Conditional Structure

if score > 90:
    print("A")
elif score > 80:
    print("B")
else:
    print("C")

What is the purpose of elif in this code?

15. Nested Conditionals

if num > 0:
    if num % 2 == 0:
        print("Even positive")

What does this nested conditional check?

16. Print Separator

print("Python", "Java", "C++", sep=" | ")

What does the sep parameter change in this output?

17. Print End Parameter

print("Hello", end="---")
print("World")

Why does “Hello—World” appear on one line?

18. String Concatenation

name = "Alice"
print("Hello " + name)

Why is + allowed here, and what would happen if you tried "Hello" + 5?

19. Multiline Comment Behavior

"""
This is a description.
It spans multiple lines.
"""

Why is this not technically a comment even though it behaves like one?

20. Multiline Print

print("Line1\nLine2\nLine3")

What role does \n play in producing the output?