Swift Array extension to insert value in a sorted array at correct index. Index is found by using binary search.

Array+Extension.swift

extension Array where Element: Comparable {
    
    //insert item to sorted array
    mutating func insertSorted(newItem item: Element) {
        let index = insertionIndexOf(elem: item) { $0 < $1 }
        insert(item, at: index)
    }
}

extension Array {
    
    //https://stackoverflow.com/a/26679191/8234523
    func insertionIndexOf(elem: Element, isOrderedBefore: (Element, Element) -> Bool) -> Int {
        var lo = 0
        var hi = self.count - 1
        while lo <= hi {
            let mid = (lo + hi)/2
            if isOrderedBefore(self[mid], elem) {
                lo = mid + 1
            } else if isOrderedBefore(elem, self[mid]) {
                hi = mid - 1
            } else {
                return mid
            }
        }
        return lo
    }
}

Usage:

Input:

let inputList = ["a", "c", "d", "g", "i", "j"]
print(inputList)

Output:

["a", "c", "d", "g", "i", "j"]

var outputList = inputList
outputList.insertSorted(newItem: "h")
outputList.insertSorted(newItem: "k")
outputList.insertSorted(newItem: "e")
outputList.insertSorted(newItem: "x")
print(outputList)

Output:

["a", "c", "d", "e", "g", "h", "i", "j", "k", "x"]