Reference · Lists

last

last(list | null) -> any

What it does

The last item of a list, or null when the list is empty. null counts as an empty list. xs[-1] is the same thing for a list that is known to have an item.

Examples

print(last([1, 2, 3]))print(last(["ann", "bob"]))print(last(split("a/b/c.txt", "/")))

3bobc.txt

Edge cases

• last([]) and last(null) are null, not an error. Give a default with ??.
• A last item that is null gives null too; check len when the difference matters.
• A list of one item: its first and last are the same item.

print(last([]), last(null), last(null) ?? "empty")print(last([1, null]), len([1, null]))print(last([7]) == first([7]))

null null emptynull 2true

Errors

An argument that is not a list or null is a runtime error, not an error value. A string is not a list: use slice with a negative start for its last characters.

print(last("abc"))

line 1: `last` expects a list as argument 1, got str

Chaining

In a pipeline last takes the list and needs no arguments: the largest after a sort, the newest of a list in order of time.

print([5, 3, 9] | sort | last)print(["pear", "fig", "apple"] | sort_by(len) | last)print("a.tar.gz" | split(".") | last)

9applegz

See also

first, max, drop, slice, reverse

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