What are some common mistakes when using filter and reduce in JavaScript?

What are some common mistakes when using filter and reduce in JavaScript?

Some common mistakes include not returning the correct value in the callback, or using them inappropriately together.

Can you give an example of a mistake with filter?

Sure! A common mistake is using filter without returning a boolean value. For instance, if you return an object instead of true or false, it won't filter correctly.

What about reduce? What mistakes do people make there?

With reduce, a frequent mistake is forgetting to return the accumulator. If you don't return it, the next iteration won't have the correct value.

How can I avoid these mistakes?

To avoid these mistakes, always ensure your callback functions return the expected values and test your code with different inputs.