我需要一种方法来删除字符串的第一个字符,这是一个空格。我正在寻找一个方法,甚至是一个扩展的字符串类型,我可以用来削减字符串的字符。
当前回答
尝试函数式编程来删除空白:
extension String {
func whiteSpacesRemoved() -> String {
return self.filter { $0 != Character(" ") }
}
}
其他回答
class SpaceRemover
{
func SpaceRemover(str :String)->String
{
var array = Array(str)
var i = array.count
while(array.last == " ")
{
var array1 = [Character]()
for item in 0...i - 1
{
array1.append(array[item])
}
i = i - 1
array = array1
print(array1)
print(array)
}
var arraySecond = array
var j = arraySecond.count
while(arraySecond.first == " ")
{
var array2 = [Character]()
if j > 1
{
for item in 1..<j
{
array2.append(arraySecond[item])
}
}
j = j - 1
arraySecond = array2
print(array2)
print(arraySecond)
}
print(arraySecond)
return String(arraySecond)
}
}
斯威夫特5 + 从字符串的前缀(开始)删除所有空白,你可以使用类似的后缀/字符串的结束
extension String {
func deletingPrefix(_ prefix: String) -> String {
guard self.hasPrefix(prefix) else { return self }
return String(self.dropFirst(prefix.count))
}
func removeWhitespacePrefix() -> String {
let prefixString = self.prefix(while: { char in
return char == " "
})
return self.deletingPrefix(String(prefixString))
}
}
快速解决方案:
用法:
let txt = " hello world "
let txt1 = txt.trimStart() // "hello world "
let txt2 = txt.trimEnd() // " hello world"
用法二:
let txt = "rr rrr rrhello world r r r r r r"
let txt1 = txt.trimStart(["r", " "]) // "hello world r r r r r r"
let txt2 = txt.trimEnd(["r", " "]) // "rr rrr rrhello world"
如果你需要移除字符串中的所有空白:
txt.replace(of: " ", to: "")
public extension String {
func trimStart(_ char: Character) -> String {
return trimStart([char])
}
func trimStart(_ symbols: [Character] = [" ", "\t", "\r", "\n"]) -> String {
var startIndex = 0
for char in self {
if symbols.contains(char) {
startIndex += 1
}
else {
break
}
}
if startIndex == 0 {
return self
}
return String( self.substring(from: startIndex) )
}
func trimEnd(_ char: Character) -> String {
return trimEnd([char])
}
func trimEnd(_ symbols: [Character] = [" ", "\t", "\r", "\n"]) -> String {
var endIndex = self.count - 1
for i in (0...endIndex).reversed() {
if symbols.contains( self[i] ) {
endIndex -= 1
}
else {
break
}
}
if endIndex == self.count {
return self
}
return String( self.substring(to: endIndex + 1) )
}
}
/////////////////////////
/// ACCESS TO CHAR BY INDEX
////////////////////////
extension StringProtocol {
subscript(offset: Int) -> Character { self[index(startIndex, offsetBy: offset)] }
subscript(range: Range<Int>) -> SubSequence {
let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
return self[startIndex..<index(startIndex, offsetBy: range.count)]
}
subscript(range: ClosedRange<Int>) -> SubSequence {
let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
return self[startIndex..<index(startIndex, offsetBy: range.count)]
}
subscript(range: PartialRangeFrom<Int>) -> SubSequence { self[index(startIndex, offsetBy: range.lowerBound)...] }
subscript(range: PartialRangeThrough<Int>) -> SubSequence { self[...index(startIndex, offsetBy: range.upperBound)] }
subscript(range: PartialRangeUpTo<Int>) -> SubSequence { self[..<index(startIndex, offsetBy: range.upperBound)] }
}
Swift 4、4.2和5
仅从前端和尾部移除空间
let str = " Akbar Code "
let trimmedString = str.trimmingCharacters(in: .whitespacesAndNewlines)
从字符串中的每一个地方删除空格
let stringWithSpaces = " The Akbar khan code "
let stringWithoutSpaces = stringWithSpaces.replacingOccurrences(of: " ", with: "")
尝试函数式编程来删除空白:
extension String {
func whiteSpacesRemoved() -> String {
return self.filter { $0 != Character(" ") }
}
}