Add string to beginning of another string

Question

Basic question

I have 2 strings. I want to add one string to another? Here's an example:

var secondString= "is your name."
var firstString = "Mike, "

Here I have 2 strings. I want to add firstString to secondString, NOT vice versa. (Which would be: firstString += secondString.)

More detail

I have 5 string

let first = "7898"
let second = "00"
let third = "5481"
let fourth = "4782"

var fullString = "\(third):\(fourth)"

I know for sure that third and fourth will be in fullString, but I don't know about first and second.

So I will make an if statement checking if second has 00. If it does, first and second won't go in fullString. If it doesn't, second will go intofullString`.

Then I will check if first has 00. If it does, then first won't go inside of fullString, and if not, it will go.

The thing is, I need them in the same order: first, second, third fourth. So in the if statement, I need a way to potentially add first and second at the beginning of fullString.

Answer 1

Re. your basic question:

 secondString = "\(firstString)\(secondString)"

or

secondString = firstString + secondString

Here is a way to insert string at the beginning "without resetting" per your comment (first at front of second):

let range = second.startIndex..<second.startIndex
second.replaceRange(range, with: first)

Re. your "more detail" question:

var fullString: String

if second == "00" {
    fullString = third + fourth
} else if first == "00" {
    fullString = second + third + fourth
} else {
    fullString = first + second + third + fourth
}