Instance Method

# max(by:)

Returns the maximum element in the sequence, using the given predicate as the comparison between elements.

## Parameters

`areInIncreasingOrder`

A predicate that returns `true` if its first argument should be ordered before its second argument; otherwise, `false`.

## Return Value

The sequence’s maximum element if the sequence is not empty; otherwise, `nil`.

## Discussion

The predicate must be a strict weak ordering over the elements. That is, for any elements `a`, `b`, and `c`, the following conditions must hold:

• `areInIncreasingOrder(a, a)` is always `false`. (Irreflexivity)

• If `areInIncreasingOrder(a, b)` and `areInIncreasingOrder(b, c)` are both `true`, then `areInIncreasingOrder(a, c)` is also `true`. (Transitive comparability)

• Two elements are incomparable if neither is ordered before the other according to the predicate. If `a` and `b` are incomparable, and `b` and `c` are incomparable, then `a` and `c` are also incomparable. (Transitive incomparability)

This example shows how to use the `max(by:)` method on a dictionary to find the key-value pair with the highest value.

Complexity: O(n), where n is the length of the sequence.

### Finding Elements

`func first(where: (Int) -> Bool) -> Int?`

Returns the first element of the sequence that satisfies the given predicate.

`func max() -> Int?`

Returns the maximum element in the sequence.

`func min() -> Int?`

Returns the minimum element in the sequence.

`func min(by: (Int, Int) -> Bool) -> Int?`

Returns the minimum element in the sequence, using the given predicate as the comparison between elements.

`func integerLessThanOrEqualTo(IndexSet.Element) -> IndexSet.Element?`

Returns an integer contained in `self` which is less than or equal to `integer`, or `nil` if a result could not be found.

`func integerGreaterThan(IndexSet.Element) -> IndexSet.Element?`

Returns an integer contained in `self` which is greater than `integer`, or `nil` if a result could not be found.

`func integerGreaterThanOrEqualTo(IndexSet.Element) -> IndexSet.Element?`

Returns an integer contained in `self` which is greater than or equal to `integer`, or `nil` if a result could not be found.

`func integerLessThan(IndexSet.Element) -> IndexSet.Element?`

Returns an integer contained in `self` which is less than `integer`, or `nil` if a result could not be found.