title: Create an Array List in C#
body: <p>I have got the problem with creating an array list in c#, Can you please help me.
  I need to create the array list to remove all the pipes that have lengths lower than 19.</p>
  
  <pre><code>namespace ConsoleApplication1
  {
      class Program
      {
          static void Main(string[] args)
          {
              ArrayList lstPipeTypes = new ArrayList();
  
              lstPipeTypes.Add(new PipesList("PVC Pipes"));
              ((PipesList)lstPipeTypes[0]).Pipes.Add(new Pipe("The blue pipe", 12));
              ((PipesList)lstPipeTypes[0]).Pipes.Add(new Pipe("The red pipe", 15));
              ((PipesList)lstPipeTypes[0]).Pipes.Add(new Pipe("The silver pipe", 6));
              ((PipesList)lstPipeTypes[0]).Pipes.Add(new Pipe("The green pipe", 52));
  
              lstPipeTypes.Add(new PipesList("Iron Pipes"));
              ((PipesList)lstPipeTypes[1]).Pipes.Add(new Pipe("The gold pipe", 9));
              ((PipesList)lstPipeTypes[1]).Pipes.Add(new Pipe("The orange pipe", 115));
              ((PipesList)lstPipeTypes[1]).Pipes.Add(new Pipe("The pink pipe", 1));
  
              lstPipeTypes.Add(new PipesList("Chrome Pipes"));
              ((PipesList)lstPipeTypes[2]).Pipes.Add(new Pipe("The grey pipe", 12));
              ((PipesList)lstPipeTypes[2]).Pipes.Add(new Pipe("The black pipe", 15));
              ((PipesList)lstPipeTypes[2]).Pipes.Add(new Pipe("The white pipe", 19));
              ((PipesList)lstPipeTypes[2]).Pipes.Add(new Pipe("The brown pipe", 60));
              ((PipesList)lstPipeTypes[2]).Pipes.Add(new Pipe("The peach pipe", 16));
  
  
              RemoveTheSmallPipes(lstPipeTypes);
          }
  
  
          public static ArrayList RemoveTheSmallPipes(ArrayList lstPipeTypes)
          {
  
              //should remove all pipes that have lengths lower than 19.
  
              return lstPipeTypes;
  
          }
      }
  
      class PipesList
      {
          public string pipeType;
          public ArrayList Pipes;
  
          public PipesList(string newBoxType)
          {
              pipeType = newBoxType;
              Pipes = new ArrayList();
          }
      }
  
      class Pipe
      {
          public string name;
          public float length;
  
          public Pipe(string newName, float newLength)
          {
              this.name = newName;
              this.length = newLength;
          }
      }
  
  
  }
  </code></pre>
  
  <p>I have created the two classes called Pipe and PipeList as well and I need to place the array list in the "RemoveTheSmallPipes" method. But I am confused now to write the rest. Please help me to remove all the pipes that have lengths lower than 19.</p>