Question

我想删除所有出现的char ==。在除最后一个之外的字符串中。

E.G：

var amazon = require('amazon-product-api');

var client = amazon.createClient({
  awsId: "aws ID",
  awsSecret: "aws Secret",
  awsTag: "aws Tag"
});

应该成为：

1.2.3.4

Answer 1

找到最后一个点的位置。
删除此位置前的所有点。

示例：

var str = "1.2.3.4"
if let idx = str.range(of: ".", options: .backwards) {
    str = str.replacingOccurrences(of: ".", with: "", range: str.startIndex..<idx.lowerBound)
}
print(str) // 123.4

Answer 2

以下是示例代码。按角色分割，将该角色添加到最后一个元素的开头，然后再将它们连接起来

let str = "1.2.3.4"
var array = str.components(separatedBy: ".")
if array.count >= 1 {
    array[array.count - 1] = "." + array[array.count - 1]
}
print(array.joined(separator: ""))

Answer 3

您可以将此简易重用作为String的扩展名。

public extension String {

    func stringByReplacingAllButLastOccurrenceOfString(target: String, withString replaceString: String) -> String {

        if let idx = self.rangeOfString(target, options: .BackwardsSearch) {
            return self.stringByReplacingOccurrencesOfString(target, withString: replaceString, range: self.startIndex..<idx.first!)
        }
        return self
    }

}

通过一些场景，你得到：

strResult = "1.2.3.4.5".stringByReplacingAllButLastOccurrenceOfString(".", withString: "")
// result "1234.5"

strResult = "1234.5".stringByReplacingAllButLastOccurrenceOfString(".", withString: "")
// result "1234.5"

strResult = "1.23.4.5".stringByReplacingAllButLastOccurrenceOfString(".", withString: "")
// result "1234.5"

strResult = "1234.5".stringByReplacingAllButLastOccurrenceOfString(".", withString: "")
// result "1234.5"

strResult = "12345".stringByReplacingAllButLastOccurrenceOfString(".", withString: "")
// result "12345"

删除除最后一个之外的所有事件

3 个答案: