🚫 1. Using = Instead of == in Conditions (C++, C#)

C#
if (x = 5) // Wrong: assigns 5 to x instead of comparing
if (x == 5) // Correct

Beginners often confuse assignment (=) with comparison (==). This can lead to unexpected bugs.

🚫 2. Indentation Issues (Python)

Python
if x == 5:
print("Hello")  # Wrong

Python relies on indentation for blocks. Forgetting or misaligning it causes errors.

🚫 3. Forgetting to Initialize Variables

C++/C#: Uninitialized variables may hold garbage values.

C#
int score;  // May contain random data!
cout << score;

Always assign default values before using.

🚫 4. Not Understanding Data Types

C#
int result = 10 / 3;  // Result: 3, not 3.33!

In C# and C++, integer division drops decimals. Use float or double when needed.

🚫 5. Using == to Compare Strings (C++, C#)

C#
string name = "John";
if (name == "John") // ❌ Not reliable in C++

In C++, use .compare() or == from the standard string class. In C#, == works, but be cautious with object references.

🚫 6. Missing Brackets or Colons

🚫 7. Infinite Loops by Mistake

C#
while x != 5:
    print("Running")  # If x is never 5, loop runs forever

Always check that your loop has an exit condition.

🚫 8. Case Sensitivity Confusion

C#
Name = "John"
print(name)  # Error: Python is case-sensitive!

Variables like Name and name are different in all three languages.

🚫 9. Misusing Logical Operators (&&, ||, and, or)

C#
if (age > 18 & hasID)  // ❌ Bitwise AND
if (age > 18 && hasID) // ✅ Logical AND

Use the correct logical operators. Python uses and, or; C++/C# use &&, ||.

🚫 10. Forgetting to Close Files or Resources

C#
file = open("data.txt", "r")
# Forgot to close it!

Always use proper file handling: