Q:
Why is the max in `map` less than the max in `flatMap`?
Why does the following code return a list of length 8 while the one in flatMap returns a list of length 3?
val xs = List(1, 2, 3, 4, 5, 6, 7, 8)
val ys = xs.map(_ + 1)
println(xs.length)
println(ys.length)
xs.max + 1
A:
Well, this is because map() applies a function to the elements of a list and returns a list of the values it got from applying the function to each element.
That is why it will be shorter.
On the other hand, flatMap() applies a function to each element of a list and returns a list of the function outputs.
So it will be longer because each element of the list will have a different length for the first element of the list.
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