key word new in array

In .Net different code syntax produces identical code.

Consider the two bits of code below:

private string myString;

public string MyString
{
  get
  {
    return myString;
  }

  set
  {
    myString = value;
  }
}

and

public string MyString {get; set;}

They both do exactly the same thing

The second block is basically just a shorthand way to create the first.

For your second Array example the C# compiler 'knows' that you want to create a new int[] and does it for you behind the scenes.

It is just a more recent way to do it to make the coders job easier.