我知道如何通过编程来做到这一点，但我相信有一种内置的方式……
我使用过的每种语言都有某种对象集合的默认文本表示，当您试图将Array与字符串连接起来或将其传递给print()函数等时，它会吐出这些文本表示。苹果的Swift语言是否有一种内置的方式，可以轻松地将数组转换为字符串，或者我们总是必须显式地对数组进行字符串化?
当前回答
Swift 2.0 Xcode 7.0 beta 6以上使用joinWithSeparator()代替join():
var array = ["1", "2", "3"]
let stringRepresentation = array.joinWithSeparator("-") // "1-2-3"
joinWithSeparator被定义为SequenceType的扩展
extension SequenceType where Generator.Element == String {
/// Interpose the `separator` between elements of `self`, then concatenate
/// the result. For example:
///
/// ["foo", "bar", "baz"].joinWithSeparator("-|-") // "foo-|-bar-|-baz"
@warn_unused_result
public func joinWithSeparator(separator: String) -> String
}
其他回答
当您想要将结构类型的列表转换为字符串时，请使用此方法
struct MyStruct {
var name : String
var content : String
}
let myStructList = [MyStruct(name: "name1" , content: "content1") , MyStruct(name: "name2" , content: "content2")]
然后像这样隐藏你的数组
let myString = myStructList.map({$0.name}).joined(separator: ",")
将产生===> "name1,name2"
对于swift 3:
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
if textField == phoneField
{
let newString = NSString(string: textField.text!).replacingCharacters(in: range, with: string)
let components = newString.components(separatedBy: NSCharacterSet.decimalDigits.inverted)
let decimalString = NSString(string: components.joined(separator: ""))
let length = decimalString.length
let hasLeadingOne = length > 0 && decimalString.character(at: 0) == (1 as unichar)
if length == 0 || (length > 10 && !hasLeadingOne) || length > 11
{
let newLength = NSString(string: textField.text!).length + (string as NSString).length - range.length as Int
return (newLength > 10) ? false : true
}
var index = 0 as Int
let formattedString = NSMutableString()
if hasLeadingOne
{
formattedString.append("1 ")
index += 1
}
if (length - index) > 3
{
let areaCode = decimalString.substring(with: NSMakeRange(index, 3))
formattedString.appendFormat("(%@)", areaCode)
index += 3
}
if length - index > 3
{
let prefix = decimalString.substring(with: NSMakeRange(index, 3))
formattedString.appendFormat("%@-", prefix)
index += 3
}
let remainder = decimalString.substring(from: index)
formattedString.append(remainder)
textField.text = formattedString as String
return false
}
else
{
return true
}
}
我的工作在NSMutableArray与componentsJoinedByString
var array = ["1", "2", "3"]
let stringRepresentation = array.componentsJoinedByString("-") // "1-2-3"
在Swift 4中
let array:[String] = ["Apple", "Pear ","Orange"]
array.joined(separator: " ")
当你也有struct数组时，你可以使用joined()来获得单个String。
struct Person{
let name:String
let contact:String
}
使用map() & joined()可以轻松生成字符串
PersonList.map({"\($0.name) - \($0.contact)"}).joined(separator: " | ")
输出:
Jhon - 123 | Mark - 456 | Ben - 789
