swift - 删除范围内的字符 :NSMakeRange equivalent in swift 3 to delete characters one by one from last index of string

Question

我有包含字符的用户输入字符串。当我点击按钮直到字符串为空时，我想从最后一个索引中一一删除这些字符 这是我的字符串变量

@IBAction func btnBackSpaceAction(_ sender: AnyObject) {
    if self.userInput.characters.count >= 1{
        let string = String(self.userInput.characters.dropLast())
        print(string)
    }
}

如何删除最后一个字符？

Answer 1

你可以尝试这样的事情

var string = "Good Morning" // Your string

@IBAction func bnuttonAction(_ sender: UIButton) { //Your button action
    string = String(string.characters.dropLast())
    if !string.isEmpty {            
        print(string)
    }
    else {
        print("String is Empty")
    }
}

输出:

Good Mornin
Good Morni
Good Morn
Good Mor
Good Mo
Good M
...