Instance Methodswift 6.0.1Swift

    index(_:offsetBy:limitedBy:)

    Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.

    func index(_ i: Int, offsetBy distance: Int, limitedBy limit: Int) -> Int?
    Mangled symbol

    ss10ArraySliceV5index_8offsetBy07limitedE0SiSgSi_S2itFWhat are these?

    FNV24: [24A8K]

    Parameters

    i

    A valid index of the array.

    distance

    The distance to offset i.

    limit

    A valid index of the collection to use as a limit. If distance > 0, limit has no effect if it is less than i. Likewise, if distance < 0, limit has no effect if it is greater than i.

    Returns

    An index offset by distance from the index i, unless that index would be beyond limit in the direction of movement. In that case, the method returns nil.

    The following example obtains an index advanced four positions from an array’s starting index and then prints the element at that position. The operation doesn’t require going beyond the limiting numbers.endIndex value, so it succeeds.

    let numbers = [10, 20, 30, 40, 50]
if let i = numbers.index(numbers.startIndex,
                         offsetBy: 4,
                         limitedBy: numbers.endIndex) {
    print(numbers[i])
}
// Prints "50"

    The next example attempts to retrieve an index ten positions from numbers.startIndex, but fails, because that distance is beyond the index passed as limit.

    let j = numbers.index(numbers.startIndex,
                      offsetBy: 10,
                      limitedBy: numbers.endIndex)
print(j)
// Prints "nil"

    The value passed as distance must not offset i beyond the bounds of the collection, unless the index passed as limit prevents offsetting beyond those bounds.

    Other members in extension

    Typealiases

    Type members

    Instance members