How can I remove the last character of a String in Swift 4?

Question

How do I remove the last character of a string in Swift 4? I used to use substring in earlier versions of Swift, but the substring method is deprecated.

Here's the code I have.

temp = temp.substring(to: temp.index(before: temp.endIndex))

Solution 1

dropLast() is your safest bet, because it handles nils and empty strings without crashing (answer by OverD), but if you want to return the character you removed, use removeLast():

var str = "String"
let removedCharacter = str.removeLast() //str becomes "Strin"
                                        //and removedCharacter will be "g"

A different function, removeLast(_:) changes the count of the characters that should be removed:

var str = "String"
str.removeLast(3) //Str

The difference between the two is that removeLast() returns the character that was removed, while removeLast(_:) does not have a return value:

var str = "String"
print(str.removeLast()) //prints out "g"

Solution 2

You can use dropLast()

You can find more information on Apple documentation

Solution 3

A literal Swift 4 conversion of your code is

temp = String(temp[..<temp.index(before: temp.endIndex)])

• foo.substring(from: index) becomes foo[index...]

• foo.substring(to: index) becomes foo[..<index]

  and in particular cases a new String must be created from the Substring result.

but the solution in the4kmen's answer is much better.