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"
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
在Swift 3.0中
extension String
{
func trim() -> String
{
return self.trimmingCharacters(in: CharacterSet.whitespaces)
}
}
你可以打电话
let result = " Hello World ".trim() /* result = "Hello World" */
其他回答
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)
下面介绍如何从字符串的开头和结尾删除所有空白。
(用Swift 2.0测试的示例。)
let myString = " \t\t Let's trim all the whitespace \n \t \n "
let trimmedString = myString.stringByTrimmingCharactersInSet(
NSCharacterSet.whitespaceAndNewlineCharacterSet()
)
// Returns "Let's trim all the whitespace"
(用Swift 3+测试的示例。)
let myString = " \t\t Let's trim all the whitespace \n \t \n "
let trimmedString = myString.trimmingCharacters(in: .whitespacesAndNewlines)
// Returns "Let's trim all the whitespace"
//Swift 4.0删除空格和新行
extension String {
func trim() -> String {
return self.trimmingCharacters(in: .whitespacesAndNewlines)
}
}
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: ","))
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