C# 进入一个类似myString.Length==1&&myString[0]>='a'&&myString[0]的检查 var result = MyBlRepository.MyBLMethod(myString); var list = new Lis

进入一个类似

myString.Length==1&&myString[0]>='a'&&myString[0]的检查
var result = MyBlRepository.MyBLMethod(myString);

var list = new List<string>
{
  "A", 
  "B", 
  "C",
  "D"
 };
 bool exists = list.Contains(myString);

bool result;
switch (myString) {
    case "A":
    case "B":
    case "C":
    case "D":
        result = true;
        break;
    default:
        result = false;
        break;
}

var expression = ReadFromConfigFile(); 
var regex = new Regex(expression);
if(regex.IsMatch(myString))
 // do work