//  StringManipulationsMore.swift  (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2015-09-09  File created.
//  2018-03-17  Modifications for Swift 4.


import Foundation

var first_string   =  "AAABBBCCCDDD"
var second_string  =  "xxxyyyzzz"

print( "\n CHARACTER POSITIONS    : 01234567890123456 " )
print( " Original first_string  : " + first_string )
print( " Original second_string : " + second_string )


first_string  = 
   String( second_string.prefix(
       upTo: second_string.index( second_string.startIndex, offsetBy: 5 ) ) )
   +

   String( first_string.suffix(
       from: first_string.index( first_string.startIndex, offsetBy: 5 ) ) )

print( " Modified first_string  : " + first_string )

var beginning_of_second_string = String( second_string.prefix(
        upTo: second_string.index( second_string.startIndex, offsetBy: 5 ) ) )

if first_string.hasPrefix( beginning_of_second_string )
{
   print( "\n The first five characters in both strings are the same." )
}


let range_of_substring = first_string.range( of: "CCCD" )

if  range_of_substring != nil 
{
   print( String( format: "\n String \"%@\" includes string \"CCCD\" in position ",
                  first_string ), terminator: "" ) 

   let substring_start_index : Int =

         first_string.distance( from: first_string.startIndex,
                                  to: range_of_substring!.lowerBound ) 

   print( substring_start_index )
}

print( "\n" )