Instance Method

index(of:)

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

Declaration

func index(of element: Character) -> String.Index?

Return Value

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

Discussion

After using index(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.

var students = ["Ben", "Ivy", "Jordell", "Maxime"]
if let i = students.index(of: "Maxime") {
    students[i] = "Max"
}
print(students)
// Prints "["Ben", "Ivy", "Jordell", "Max"]"

See Also

Finding Characters

func contains(Character)

Returns a Boolean value indicating whether the sequence contains the given element.

func contains(where: (Character) -> Bool)

Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.

func first(where: (Character) -> Bool)

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

func index(where: (Character) -> Bool)

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

func max()

Returns the maximum element in the sequence.

func max(by: (Character, Character) -> Bool)

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

func min()

Returns the minimum element in the sequence.

func min(by: (Character, Character) -> Bool)

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