问为什么Console.ReadLine()忽略空格？

EN

using System;
using System.Collections.Generic;

namespace CrackingTheCodingInterView
{
    public class CheckUniqueChars
    {
        public static void Main()
        {
            string inputString;

            bool checkUnique = false;

            Console.WriteLine("Enter string to check for unique chars: ");

            inputString = Console.ReadLine();

            checkUnique = UniqueChars(inputString);

            Console.WriteLine("String is: {0}", inputString);

            string output = checkUnique ? "has" : "does not have";

            Console.WriteLine("The input string {0} unique chars", output);

        }

        public static bool UniqueChars(string inputString)
        {
            List<char> uniqueCharsList = new List<char>();

            foreach(char c in inputString)
            {
                if(uniqueCharsList.Contains(c))
                {
                    return false;
                }
                else
                {
                    uniqueCharsList.Add(c);
                }
            }

            return true;
        }
    }
}