Instance Method

# firstIndex(of:)

Returns the first index where the specified value appears in the collection.

## Declaration

Available when Element conforms to Equatable.

## Parameters

`element`

An element to search for in the collection.

## Return Value

The first index where `element` is found. If `element` is not found in the collection, returns `nil`.

## Discussion

After using `firstIndex(of:)` to find the position of a particular element in a collection, you can use it to access the element by subscripting. This example shows how you can modify one of the names in an array of students.

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

### Finding Elements

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

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

`func firstIndex(where: (Bound) -> Bool) -> Bound?`

Returns the first index in which an element of the collection satisfies the given predicate.

`func last(where: (Bound) -> Bool) -> Bound?`

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

`func lastIndex(of: Bound) -> Bound?`

Returns the last index where the specified value appears in the collection.

`func lastIndex(where: (Bound) -> Bool) -> Bound?`

Returns the index of the last element in the collection that matches the given predicate.

`func min() -> Bound?`

Returns the minimum element in the sequence.

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

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

`func max() -> Bound?`

Returns the maximum element in the sequence.

`func max(by: (Bound, Bound) -> Bool) -> Bound?`

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