If statement execution flow in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if-else blocks

What is the output of this Python code?

Python

x = 10
if x > 5:
    if x > 8:
        print("A")
    else:
        print("B")
else:
    print("C")

A A

B B

C C

D No output

💡 Hint

Check the conditions step by step from top to bottom.

x is 10, which is greater than 5, so the first if is true. Then inside, x is also greater than 8, so it prints "A".

❓ Predict Output

intermediate

If-elif-else execution output

What will be printed when this code runs?

Python

num = 0
if num > 0:
    print("Positive")
elif num == 0:
    print("Zero")
else:
    print("Negative")

A Zero

B No output

C Negative

D Positive

💡 Hint

Check which condition matches the value of num.

num is 0, so the elif condition num == 0 is true, printing "Zero".

❓ Predict Output

advanced

Output with multiple if statements

What is the output of this code snippet?

Python

a = 3
if a > 2:
    print("X")
if a > 4:
    print("Y")
else:
    print("Z")

A

X
Y

B

X
Z

C Z

D X

💡 Hint

Remember that the else belongs to the second if only.

a is 3, so first if prints "X". Second if a > 4 is false, so else prints "Z".

❓ Predict Output

advanced

If statement with logical operators

What will this code print?

Python

x = 7
y = 5
if x > 5 and y < 10:
    print("Yes")
elif x > 5 or y > 10:
    print("Maybe")
else:
    print("No")

A No

B Maybe

C Yes

D SyntaxError

💡 Hint

Check the first condition carefully with both parts.

x is 7 > 5 and y is 5 < 10, so first if condition is true, printing "Yes".

❓ Predict Output

expert

If statement with assignment expression

What is the output of this code?

Python

if (n := 4) > 3:
    print(n * 2)
else:
    print(n / 2)

A 4

B 2.0

C SyntaxError

D 8

💡 Hint

The walrus operator assigns and returns the value in the condition.

n is assigned 4, which is greater than 3, so it prints 4 * 2 = 8.

Practice

1. What does an if statement do in Python?

easy

A. It stores data in a list.

B. It repeats code multiple times.

C. It runs code only if a condition is true.

D. It defines a new function.

Solution

1. Step 1: Understand the purpose of if

   An if statement checks a condition and runs code only if that condition is true.

2. Step 2: Compare with other options

   Repeating code is done by loops, storing data is done by lists, and defining functions uses def.

3. Final Answer:

   It runs code only if a condition is true. -> Option C

4. Quick Check:

   if runs code if condition true [OK]

Hint: If checks condition; runs code only when true [OK]

Common Mistakes:

• Confusing if with loops
• Thinking if stores data
• Mixing if with function definition

2. Which of the following is the correct syntax for an if statement in Python?

easy

A. if x > 5 then:

B. if x > 5:

C. if (x > 5) {}

D. if x > 5 then

Solution

1. Step 1: Recall Python if syntax

   Python uses a colon : after the condition and no parentheses or 'then'.

2. Step 2: Check each option

   if x > 5: uses if x > 5: which is correct. Others use 'then' or braces which are not Python syntax.

3. Final Answer:

   if x > 5: -> Option B

4. Quick Check:

   Python if ends with colon [OK]

Hint: Python if ends with colon, no 'then' or braces [OK]

Common Mistakes:

• Adding 'then' after condition
• Using braces {} like other languages
• Forgetting the colon at the end

3. What will be the output of this code?

age = 20
if age < 18:
    print("Child")
elif age < 65:
    print("Adult")
else:
    print("Senior")

medium

A. Adult

B. Senior

C. Child

D. No output

Solution

1. Step 1: Check the value of age

   The variable age is 20.

2. Step 2: Evaluate conditions in order

   First condition age < 18 is false (20 is not less than 18). Second condition age < 65 is true (20 is less than 65), so it prints "Adult" and skips the else.

3. Final Answer:

   Adult -> Option A

4. Quick Check:

   20 is less than 65, prints Adult [OK]

Hint: Check conditions top to bottom; first true runs [OK]

Common Mistakes:

• Printing Child for age 20
• Ignoring elif and jumping to else
• Thinking no output if first condition false

4. Find the error in this code:

score = 75
if score >= 90
    print("Excellent")
elif score >= 60:
    print("Pass")
else:
    print("Fail")

medium

A. score variable not defined

B. Wrong indentation on print statements

C. Using elif instead of else if

D. Missing colon after first if condition

Solution

1. Step 1: Check syntax of if statement

   The first if line is missing a colon : at the end, which is required in Python.

2. Step 2: Verify other parts

   Indentation and elif usage are correct. The variable score is defined.

3. Final Answer:

   Missing colon after first if condition -> Option D

4. Quick Check:

   Every if needs a colon [OK]

Hint: Check colons after all if/elif/else lines [OK]

Common Mistakes:

• Forgetting colon after if condition
• Confusing elif with else if syntax
• Incorrect indentation of print lines

5. You want to print "Positive", "Zero", or "Negative" based on a number's value. Which code correctly uses if, elif, and else to do this?

hard

A. if num > 0:
print("Positive")
elif num == 0:
print("Zero")
else:
print("Negative")

B. if num > 0:
print("Positive")
if num == 0:
print("Zero")
else:
print("Negative")

C. if num > 0:
print("Positive")
else if num == 0:
print("Zero")
else:
print("Negative")

D. if num > 0:
print("Positive")
elif num < 0:
print("Zero")
else:
print("Negative")

Solution

1. Step 1: Understand correct if-elif-else structure

   Use if for first condition, elif for the second, and else for all other cases.

2. Step 2: Check each option

   if num > 0: print("Positive") elif num == 0: print("Zero") else: print("Negative") correctly uses elif and else. if num > 0: print("Positive") if num == 0: print("Zero") else: print("Negative") uses two separate if statements which can cause multiple prints. if num > 0: print("Positive") else if num == 0: print("Zero") else: print("Negative") uses invalid syntax else if. if num > 0: print("Positive") elif num < 0: print("Zero") else: print("Negative")'s elif num < 0 will print "Zero" for negative numbers and "Negative" for zero incorrectly.

3. Final Answer:

   if num > 0: print("Positive") elif num == 0: print("Zero") else: print("Negative") -> Option A

4. Quick Check:

   Use if, elif, else for exclusive conditions [OK]

Hint: Use if, elif, else for clear exclusive choices [OK]

Common Mistakes:

• Using multiple separate ifs causing multiple outputs
• Writing else if instead of elif
• Overlapping conditions causing wrong output