Is there a way to create a String from utf16 array in swift?

Question

We know that String.utf16 provides the codeunits or String.unicodeScalars provides the scalars.

If we manipulate the codeunits and unicodeScales by removing some ele

Answer 1

Here it is.

extension String {
    static func fromUTF16Chars(utf16s:UInt16[]) -> String {
        var str = ""
        for var i = 0; i < utf16s.count; i++ {
            let hi = Int(utf16s[i])
            switch hi {
            case 0xD800...0xDBFF:
                let lo = Int(utf16s[++i])
                let us = 0x10000
                    + (hi - 0xD800)*0x400 + (lo - 0xDC00)
                str += Character(UnicodeScalar(us))
            default:
                str += Character(UnicodeScalar(hi))
            }
        }
        return str
    }
}

let str = "aαあ                                                                    

                                                        
            

Answer 2

Update for Swift 2.1:

You can create a String from an array of UTF-16 characters with the

public init(utf16CodeUnits: UnsafePointer<unichar>, count: Int)

initializer. Example:

let str = "H€llo