Conditional Statements Debugging Quiz: Test Your Understanding

📚 Quick Study Guide: Conditional Statement Debugging

• 💡 Understanding Conditional Logic: Conditional statements (if, else if/elif, else) control program flow based on whether a condition is true or false.
• 🚨 Common Syntax Errors:
  • 📝 Missing colons (:) in Python.
  • 🔗 Unmatched curly braces ({}) in C++, Java, JavaScript.
  • 🚫 Missing semicolons (;) at the end of statements in C++, Java, JavaScript.
• 🧠 Logical Errors:
  • ❌ Incorrect comparison operators (e.g., using = instead of == for comparison).
  • 🔄 Flawed boolean logic (e.g., using AND where OR is needed, or vice-versa).
  • 🔢 Incorrect order of conditions (e.g., placing a general condition before a more specific one).
  • 🎯 Off-by-one errors in range checks.
• 🛠️ Debugging Strategies:
  • 🖨️ Use print() or console.log() statements to trace variable values and execution path.
  • 🔍 Step through code line-by-line using an IDE's debugger.
  • 🔬 Isolate the problematic code block and test with various inputs.
  • 🤔 Carefully review the problem statement and your logic against expected behavior.
• ⚖️ Truthiness & Falsiness: Be aware of how different languages evaluate non-boolean values in a conditional context (e.g., 0, empty strings, null, undefined are often "falsy").

🎯 Practice Quiz: Conditional Statements Debugging

Identify the error in each code snippet or determine its output.

Question 1:

# Python
score = 85
if score > 90
    print("Excellent!")
else:
    print("Good effort.")

What is the primary error in this Python code?

1. Missing indentation for the print statement.
2. Incorrect comparison operator.
3. Missing colon after the if condition.
4. The else statement is unnecessary.

Question 2:

// Java
int age = 17;
String status;
if (age = 18) {
    status = "Adult";
} else {
    status = "Minor";
}
System.out.println(status);

What will be the output of this Java code?

1. "Adult"
2. "Minor"
3. Compilation Error
4. Runtime Error

Question 3:

// JavaScript
let temp = 25;
if (temp < 0 || temp > 30) {
    console.log("Extreme temperature.");
} else if (temp >= 0 && temp <= 20) {
    console.log("Cool or mild.");
} else {
    console.log("Warm.");
}

What will be printed to the console?

1. "Extreme temperature."
2. "Cool or mild."
3. "Warm."
4. Nothing, it's an error.

Question 4:

# Python
x = 10
if x > 5:
    if x < 15:
        print("X is between 5 and 15.")
else:
    print("X is not greater than 5.")

What will be the output of this Python code?

1. "X is between 5 and 15."
2. "X is not greater than 5."
3. Syntax Error
4. No output.

Question 5:

// C++
int num = 0;
if (num) { // This checks if num is non-zero
    std::cout << "Number is truthy." << std::endl;
} else {
    std::cout << "Number is falsy." << std::endl;
}

What will be the output of this C++ code?

1. "Number is truthy."
2. "Number is falsy."
3. Compilation Error
4. Runtime Error

Question 6:

// JavaScript
let isLoggedIn = false;
let isAdmin = true;
if (isLoggedIn && isAdmin) {
    console.log("Admin logged in.");
} else if (isLoggedIn || isAdmin) {
    console.log("User or Admin logged in.");
} else {
    console.log("Not logged in.");
}

What will be printed to the console?

1. "Admin logged in."
2. "User or Admin logged in."
3. "Not logged in."
4. Compilation Error.

Question 7:

# Python
grade = 75
if grade >= 90:
    result = "A"
elif grade >= 80:
    result = "B"
elif grade >= 70:
    result = "C"
else:
    result = "F"
print(result)

What will be the output of this Python code?

1. "A"
2. "B"
3. "C"
4. "F"