是否斯威夫特有一个修剪方法的字符串?例如:
let result = " abc ".trim()
// result == "abc"
当前回答
您还可以发送您想要修剪的字符
extension String {
func trim() -> String {
return self.trimmingCharacters(in: .whitespacesAndNewlines)
}
func trim(characterSet:CharacterSet) -> String {
return self.trimmingCharacters(in: characterSet)
}
}
validationMessage = validationMessage.trim(characterSet: CharacterSet(charactersIn: ","))
其他回答
extension String {
/// EZSE: Trims white space and new line characters
public mutating func trim() {
self = self.trimmed()
}
/// EZSE: Trims white space and new line characters, returns a new string
public func trimmed() -> String {
return self.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
}
}
从我的这个回购:https://github.com/goktugyil/EZSwiftExtensions/commit/609fce34a41f98733f97dfd7b4c23b5d16416206
我创建了这个函数，允许输入字符串并返回由任意字符修剪的字符串列表
func Trim(input:String, character:Character)-> [String]
{
var collection:[String] = [String]()
var index = 0
var copy = input
let iterable = input
var trim = input.startIndex.advancedBy(index)
for i in iterable.characters
{
if (i == character)
{
trim = input.startIndex.advancedBy(index)
// apennding to the list
collection.append(copy.substringToIndex(trim))
//cut the input
index += 1
trim = input.startIndex.advancedBy(index)
copy = copy.substringFromIndex(trim)
index = 0
}
else
{
index += 1
}
}
collection.append(copy)
return collection
}
As在swift中没有找到这样做的方法(在swift 2.0中编译和工作完美)
Swift 5和4.2
let trimmedString = " abc ".trimmingCharacters(in: .whitespaces)
//trimmedString == "abc"
是的，你可以这样做:
var str = " this is the answer "
str = str.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
print(srt) // "this is the answer"
CharacterSet实际上是一个非常强大的工具，用于创建修剪规则，比. whitespacesandnewlines等预定义集更灵活。
例如:
var str = " Hello World !"
let cs = CharacterSet.init(charactersIn: " !")
str = str.trimmingCharacters(in: cs)
print(str) // "Hello World"
将字符串截断为特定长度
如果你已经输入了一段句子/文本，你想只保存指定长度的文本。将以下扩展添加到类中
extension String {
func trunc(_ length: Int) -> String {
if self.characters.count > length {
return self.substring(to: self.characters.index(self.startIndex, offsetBy: length))
} else {
return self
}
}
func trim() -> String{
return self.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
}
}
Use
var str = "Lorem Ipsum is simply dummy text of the printing and typesetting industry."
//str is length 74
print(str)
//O/P: Lorem Ipsum is simply dummy text of the printing and typesetting industry.
str = str.trunc(40)
print(str)
//O/P: Lorem Ipsum is simply dummy text of the
