多个return和一个return

//一个return
namespace CleanCSharp.Methods.Dirty
{
    class MethodExitPoints
    {
        public string GenerateAgeAppropriateGreeting(
        int customerAgeInYears)
        {
            string greeting;
            if (customerAgeInYears < )
            {
                greeting = "Yo!";
            }
            else if (customerAgeInYears < )
            {
                greeting = "Hi there";
            }
            else
            {
                greeting = "Dear Sir/Madam";
            }
            return greeting;
        }
    }
}

//多个return
namespace CleanCSharp.Methods.Clean
{
    class MethodExitPoints
    {
        public string GenerateAgeAppropriateGreeting(
        int customerAgeInYears)
        {
            if (customerAgeInYears < )
            {
                return "Yo!";
            }
            if (customerAgeInYears < )
            {
                return "Hi there";
            }
            return "Dear Sir/Madam";
        }
    }
}