Get index for closest value in array-CodePudding

Using the code from this answer to find the closest value in an array: https://stackoverflow.com/a/62159057

func closestMatch(values: [Int64], inputValue: Int64) -> Int64? {
   return (values.reduce(values[0]) { abs($0-inputValue) < abs($1-inputValue) ? $0 : $1 })
}

How can I get the index of the item that matches closest instead of its value?

CodePudding user response：

Because the array is sorted, a fast solution would be to do a binary search.

Should be easy to modify this implementation (or others in the same post) to fit your purpose.

CodePudding user response：

Solved it with firstIndex. Not super elegant but it works.

func closestMatch(values: [Int], inputValue: Int) -> Int? {
    let match = values.reduce(values[0]) { abs($0-inputValue) < abs($1-inputValue) ? $0 : $1 }
    let index = values.firstIndex(where: {$0 == match})
    return index
}