Comparing Arrays in C#

I am trying to compare two arrays with eachother. I tried this code and got the following errors

static bool ArraysEqual(Array a1, Array a2)
{
    if (a1 == a2)
        return true;

    if (a1 == null || a2 == null)
        return false;

    if (a1.Length != a2.Length)
        return false;

    IList list1 = a1, list2 = a2; //error CS0305: Using the generic type 'System.Collections.Generic.IList<T>' requires '1' type arguments
    for (int i = 0; i < a1.Length; i++)
    {
        if (!Object.Equals(list1[i], list2[i])) //error CS0021: Cannot apply indexing with [] to an expression of type 'IList'(x2)
            return false;
    }
    return true;
}

Why do i get that error? i went for a low tech solution and did this which works fine but i need to copy/paste it several times for each type.

static bool ArraysEqual(byte[] a1, byte[] a2)
{
    if (a1 == a2)
        return true;

    if (a1 == null || a2 == null)
        return false;

    if (a1.Length != a2.Length)
        return false;

    for (int i = 0; i < a1.Length; i++)
    {
        if (a1[i] != a2[i])
            return false;
    }
    return true;
}

From stackoverflow

• I think IList has to be specified like this:

  IList<string> list1 = a1, list2 = a2;
  

• "Why do i get that error?" - probably, you don't have "using System.Collections;" at the top of the file - only "using System.Collections.Generic;" - however, generics are probably safer - see below:

  static bool ArraysEqual<T>(T[] a1, T[] a2)
  {
      if (ReferenceEquals(a1,a2))
          return true;
  
      if (a1 == null || a2 == null)
          return false;
  
      if (a1.Length != a2.Length)
          return false;
  
      EqualityComparer<T> comparer = EqualityComparer<T>.Default;
      for (int i = 0; i < a1.Length; i++)
      {
          if (!comparer.Equals(a1[i], a2[i])) return false;
      }
      return true;
  }
  

  acidzombie24 : Thank you for the 2nd time today Marc :D

• Providing that you have LINQ available and don't care too much about performance, the easiest thing is the following:

  var arraysAreEqual = Enumerable.SequenceEquals(a1, a2);
  

  Joel Mueller : Or just a1.SequenceEquals(a2). What leads you to believe this would perform any worse than the accepted answer?

  Joel Mueller : I suppose the enumerable version can't rely on comparing lengths, so the accepted answer would be faster in cases where the arrays being compared were of different lengths.

  Noldorin : @Joel: That's essentially the reason. The SequenceEquals method uses enumerators, which means instantiating an iterator and then making numerous function calls to loop through it, all adding overhead. Normally I wouldn't think twice about using this method - it was just a small caveat.