get first element of list haskell code example

Example 1: first element in list haskell

list = [1, 2, 3]

head :: [a] -> a
head (x:_) = x

head list -- 1

Example 2: remove first element list haskell

a = [1, 2, 3, 4]
b = tail a
  
-- b == [2, 3, 4]

Example 3: haskell append to list

1 : [2, 3]
--return [1, 2, 3]

Example 4: haskell list element at index

-- the "!!" operator return the n-th element from the list
-- *this is zero based

"string" !! 2 --> "r"

[10, 20, 30, 40] !! 1 --> 20