Question

假设：

我需要分割并创建字符串集合的字符串dayCodes（即"MWF"或"MRFU"），以便我可以得到星期几字符串的列表（即{ {1}}或"Monday", "Wednesday", "Friday"）。

"Monday", "Thursday", "Friday", "Sunday"

问题：

问题在于你不能将// this causes a run-time exception because you can't cast Char to String var daysArray = days.ToCharArray().Cast<string>().ToArray(); // for each dayCode, overwrite the code with the day string. for (var i = 0; i < daysArray.Length; i++) { switch (daysArray[i]) { case "M": daysArray[i] = "Monday"; break; case "T": daysArray[i] = "Tuesday"; break; case "W": daysArray[i] = "Wednesday"; break; case "R": daysArray[i] = "Thursday"; break; case "F": daysArray[i] = "Friday"; break; case "S": daysArray[i] = "Saturday"; break; case "U": daysArray[i] = "Sunday"; break; } } daysArray[daysArray.Length - 1] = "and " + daysArray[daysArray.Length - 1]; return string.Join(", ", daysArray);强制转换为Char，我认为这是有意义的，因为一个不是从另一个继承的。您仍然认为编译器会将String强制转换为一个字符长Char。

有没有快速的方法（比如使用String）这样做，所以我不必从头开始创建Cast<string>()？

Answer 1

只需使用char.ToString()即可：

var daysArray = days.ToCharArray().Select( c => c.ToString()).ToArray();

或者，在我的脑海中有一个更好的解决方案，为什么不直接将字符串与字典一起用于映射：

var daysArray = days.Select( c => dayMapping[c]).ToArray();

dayMapping只有Dictionary<char, string>映射到全天名称：

Dictionary<char, string> dayMapping = new Dictionary<char,string>()
{
    {  'M', "Monday" },
    {  'T', "Tuesday" }
    //and so on
}

Answer 2

char[] daysCodeArray = days.ToCharArray();
string[] daysArray = daysCodeArray.Select(el =>
{
    switch (el)
    {
        case 'M':
            return "Monday";

        case 'T':
            return "Tuesday";

        case 'W':
            return "Wednesday";

        case 'R':
            return "Thursday";

        case 'F':
            return "Friday";

        case 'S':
            return "Saturday";

        case 'U':
            return "Sunday";
     }
     throw new ArgumentException("Invalid day code");
}).ToArray();

如果需要，可以将lambda更改为单独的方法。

Answer 3

你可以这样做：

            var dayCode = "MWF";
            var daysArray = new List<string>();
            var list = new Dictionary<string, string>{
                {"M", "Monday"},
                {"T", "Tuesday"},
                {"W", "Wednesday"},
                {"R", "Thursday"},
                {"F", "Friday"},
                {"S", "Saturday"},
                {"U", "Sunday"}
            };

            for(int i = 0,max = dayCode.Length; i < max; i++)
            {
                var tmp = dayCode[i].ToString();
                if(list.ContainsKey(tmp))
                {
                    daysArray.Add(list[tmp]);
                }
            }
            Console.WriteLine(string.Join(",", daysArray));

输出：

enter image description here

Answer 4

在标题中回答任何在搜索中发现此问题的人...（不是所描述的问题......这是之前的帖子之一。）

var t =＆＃34; ABC＆＃34;;
var s = t.ToCharArray（）。选择（c =＆gt; c.ToString（））。ToArray（）;

如何将char数组转换为字符串数组？

4 个答案: