无法从“字符串”转换为“system.collections.generic.list”

Question

I struggle with a procedural proggramming exercise. I have to call the method, but when i hover above Consecutive(input) it says:

Cannot convert from 'string' to 'system.collections.generic.list.

I don't know how to bypass this because i frankly don't know how to convert the string to system.collections.generic.list. This is the code i use:

using System;
using System.Collections.Generic;

namespace HelloWorld
{
    internal class Program
    {
        public static void Main(string[] args)
        {
            Console.Write("Enter a few numbers (eg 1-2-3-4): ");
            var input = Console.ReadLine();
            Console.WriteLine(Consecutive(input));
        }

        public static bool Consecutive(List<int> input)
        {
            var numbers = new int[input.Count];
            input.CopyTo(numbers);
            Array.Sort(numbers);
            for (var i = 1; i < numbers.Length; i++)
            {
                if (numbers[i] != numbers[i - 1] + 1)
                    return false;
            }
           return true;
        }
     }
 }

Answer 1

Console.ReadLine() returns string instead of list of integer. You need to convert this string into List and pass it to Consecutive(List<int>) fucntion

...
var input = Console.ReadLine();
//Additional line to convert string to List<string>
var processedInput = Array.ConvertAll(input.Split('-'), int.Parse).ToList();
Console.WriteLine(Consecutive(input));

...

---

Explanation of conversion of string to List<int> :

• First we are splitting input string by - as a delimiter. Array.ConvertAll() converts IEnumerable<string> to int. .ToList() convert array of integers to List<int> .

---

If you want to use TryParse to parse integer, then you can use out variable feature of C#7.

//This feature is available from C#7. 
//Here if input string fails to parse string to int, it will store 0  as default.
var processedInput = Array.ConvertAll(
          input.Split('-'), x => int.TryParse(x, out var i) ? i : 0)
          .ToList();

Answer 2

You need to convert String to List,

var input = Console.ReadLine();
var inputs = input.Split("-").Select(int.Parse).ToList();
Console.WriteLine(Consecutive(inputs));