Swift5中String、数组相互转换

1、采用 Array(str)、String(array) 方法

String转Character数组：Array(str)
Character数组转String：String(array)

let test = "i like ios"
let array = Array(test)     //[Character]
let string = String(array)  //String
print(array)
print(string)

结果打印：

[“i”, " ", “l”, “i”, “k”, “e”, " ", “i”, “o”, “s”]
i like ios

2、采用String.components(separatedBy: " ")、[String].joined(separator: " ")

String转[String]数组：String.components(separatedBy: " ")
[String]数组转String：[String].joined(separator: " ")

let test = "i like ios"
let array = test.components(separatedBy: " ")

let intArray = [1,2,3,4,5]
let dataArray = intArray.map(String.init)
let resultString = dataArray.joined(separator: "")
print(array)
print(resultString)

结果打印：

[“i”, “like”, “ios”]
12345

3、采用String.index(吐槽一下：这api真不好用)

String获取指定index的Character：String[String.index]
String根据index区间获取SubString：String(String[index_1...index_2])

let test = "i like ios"
let char_0 = test[test.index(test.startIndex, offsetBy: 0)]
let char_8 = test[test.index(test.startIndex, offsetBy: 8)]
let beginIndex = test.index(test.startIndex, offsetBy: 0)
let endIndex = test.index(test.startIndex, offsetBy: 8)
let subString = String(test[beginIndex...endIndex])
print(char_0)
print(char_8)
print(subString)

结果打印：

i
o
i like io

tips:

swift里的字符、字符串处理api比较多，在此记录几个经常使用的swift字符相关处理技巧

let charOfA = Character("A")
let uInt8Value = charOfA.asciiValue!            //Character转UInt8
let char = Character(UnicodeScalar(uInt8Value)) //UInt8转Character

let intArray = [1,2,3,4,5,6]
let strArray = intArray.map(String.init)       //[Int]转[String]

let str_Array = ["123","01","xx","000"]
let int_Array = str_Array.map(Int.init)        //[String]转[Int?] 因为有的字符串无法转int,该index存在且为nil