What are some common errors when using map and filter in programming?

What are some common errors when using map and filter in programming?

Some common errors include using the wrong data type, forgetting to return a value, or not handling undefined values.

Can you give me an example of a wrong data type error?

Sure! If you try to use map on an object instead of an array, it will throw an error because map is not a function on objects.

What about forgetting to return a value?

If you forget to return a value in a map function, you'll end up with an array of undefined values.

How can I handle undefined values in my filter?

You can check for undefined values in your filter condition, like this: array.filter(item => item !== undefined).