我想删除char ==的所有出现。在字符串中,最后一个。
例如:
1.2.3.4
应该成为:
123.4
- 找到最后一个点的位置。
- 删除此位置之前的所有点。
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
这是示例代码。由您的角色分开,将该字符添加到最后一个元素的开头,然后将它们加入
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: ""))
您可以使此easilt可重复使用作为字符串上的扩展名。
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
}
}
在几个方案中运行,您会得到:
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"