How do I concatenate strings in Swift?

Question

How to concatenate string in Swift?

In Objective-C we do like

NSString *string = @\"Swift\";
NSString *resultStr = [string stringByAppen         


        

Answer 1

Concatenation refers to the combining of Strings in Swift. Strings may contain texts, integers, or even emojis! There are many ways to String Concatenation. Let me enumerate some:

Same String

Using +=

This is useful if we want to add to an already existing String. For this to work, our String should be mutable or can be modified, thus declaring it as a Variable. For instance:

var myClassmates = "John, Jane"
myClassmates += ", Mark" // add a new Classmate
// Result: "John, Jane, Mark"

Different Strings

If we want to combine different Strings together, for instance:

let oldClassmates = "John, Jane" 
let newClassmate = "Mark"

We can use any of the following:

1) Using +

let myClassmates = oldClassmates + ", " + newClassmate
// Result: "John, Jane, Mark"

Notice that the each String may be a Variable or a Constant. Declare it as a Constant if you're only gonna change the value once.

2) String Interpolation

let myClassmates = "\(oldClassmates), \(newClassmate)"
// Result: "John, Jane, Mark"

3) Appending

let myClassmates = oldClassmates.appending(newClassmate)
// Result: "John, Jane, Mark"

Refer to Strings & Characters from the Swift Book for more.

Update: Tested on Swift 5.1