How to append a character to a string in Swift?

append append(c: Character) IS the right method but your code has two other problems.

The first is that to iterate over the characters of a string you must access the String.characters property.

The second is that the append method doesn't return anything so you should remove the newStr.

The code then looks like this:

for aCharacter : Character in aString.characters {
    var str:String = ""
    str.append(aCharacter)
    // ... do other stuff
}

Another possible option is

var s: String = ""
var c: Character = "c"
s += "\(c)"

This also works

var newStr:String = str + String(aCharacter)

Update for the moving target that is Swift:

Swift no longer has a + operator that can take a String and an array of characters. (There is a string method appendContentsOf() that can be used for this purpose).

The best way of doing this now is Martin R’s answer in a comment below:

var newStr:String = str + String(aCharacter)

Original answer: This changed in Beta 6. Check the release notes.I'm still downloading it, but try using:

var newStr:String = str + [aCharacter]