What is the difference between map and flatMap?

Can you explain the difference between map and flatMap?

Sure! Both map and flatMap are used to transform data, but they work differently. Map applies a function to each element and returns a new array of the same structure. FlatMap, on the other hand, applies a function and then flattens the result into a single array.

Can you give me an example of each?

Of course! For map, if you have an array of numbers and you want to double each number, you'd use map. For flatMap, if you have an array of arrays and you want to combine them into a single array, flatMap would be the way to go.

What happens if the function in flatMap returns an array?

If the function in flatMap returns an array, flatMap will concatenate all those arrays into a single array, effectively flattening the structure.

Are there any performance differences between the two?

Yes, flatMap can be less efficient than map because it involves an additional step of flattening the array. However, the difference is usually negligible unless you're working with large datasets.