c# - List inside list does not print elements, instead shows System.Collections.Generic.List`1[System.Object]

Question

I have a list which contains three items. First element is integer, second one is also an integer and third one is another list. By using for each loop I'm able to print these items.

List<object> mainList= new List<object>();

mainList.Add(binRead.ReadInt32()); // Reads first integer ant adds to mainList
mainList.Add(binRead.ReadInt32()); // Reads second integer ant adds to mainList

List<object> avlDataList = new List<object>();

for(int i=0; i<n; i++)
{
  // Reads some data and adds it to avlDataList
}

mainList.Add(avlDataList); // Adds that list to mainList

foreach(var i in mainList)
{
   Console.WriteLine(i); // Prints items      
}

I get this output:

8
1
System.Collections.Generic.List`1[System.Object]

How can I modify my code to see what's inside of that list instead of getting this message? That avlDataList list has 10 elements. So i would like to see 12 elements in total.

Answer 1

Try use code below:

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        List<object> mainList = new List<object>();

        mainList.Add(1); 
        mainList.Add(2); 

        List<object> avlDataList = new List<object>();

        for (int i = 0; i < 10; i++)           
            avlDataList.Add(100 + i);  

        mainList.Add(avlDataList); 

        foreach (var i in mainList)
        {
            if (i.GetType() != avlDataList.GetType())
                Console.WriteLine(i);  

            if (i.GetType() == avlDataList.GetType())                
                foreach (var ii in avlDataList)
                    Console.WriteLine(ii); 
        }
    }
}

output: 1 2 100 101 102 103 104 105 106 107 108 109