Swift String Array 之間轉換及取得字串或陣列中的前5筆資料。

//原始資料

let sample_str = "0123456789"

print(sample_str)         //....0123456789

        

//String 取得前5個字串

let sample_sring_5 =  sample_str[..<sample_str.index(sample_str.startIndex, offsetBy: 5)]

print(sample_sring_5)      //....01234

        

//String 轉 Array

var sample_str_array = Array(sample_str)

print(sample_str_array)     //....["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]

        

//Array 取得前5筆陣列值

let sample_array_5 = sample_str_array[0...4]

print(sample_array_5)       //....["0", "1", "2", "3", "4"]

        

//Array 轉 String

let sample_array_2_str = String(sample_array_5)

print(sample_array_2_str)   //....01234