Does string concatenation in Swift make a new copy?

Question

I can concatenate two strings in Swift like this:

var c = "Hello World" c += "!"

Does this create a new string? (Allocating a new block of memory, copying over the original string, concatenating the "!" string and returning the new memory.) Or, does it update the original string in place (only allocating a new block of memory if the original block can't fit the character).

Answer 1

No, it does not make a new copy. As you can see, the original string has changed.But the address remains same.