What are some common mistakes in Python and JavaScript?

What are some common mistakes in Python and JavaScript?

Some common mistakes in Python include using mutable default arguments and forgetting to use 'self' in class methods. In JavaScript, common issues are not using 'strict mode' and confusing '==' with '==='.

Can you explain why using mutable default arguments is a mistake?

Sure! Using mutable default arguments can lead to unexpected behavior because the default value is shared across all calls to the function. If you modify it, the change persists in subsequent calls.

What about the difference between '==' and '===' in JavaScript?

The '==' operator checks for equality after converting the operands to a common type, while '===' checks for both value and type equality, making it a safer choice.

How can I avoid these mistakes in my code?

To avoid these mistakes, always use immutable types as default arguments in Python, and prefer '===' over '==' in JavaScript. Additionally, consider using linters and code reviews.