Best way to detect forat, last and middle array elements

Question

Hi all,

I have a string array: MyStringArray. I need to distinguish between the first, last and middle elements.

Currently, this is what I am doing:

           string[] MyStringArray = { "A", "B", "C", "D", "Z" };

            for (int i = 0; i < MyStringArray.Length; i++)
            {

                if (i == 0)
                {
                    //Do stuff for first element.
                    MessageBox.Show("First element: " + MyStringArray[i]);
                }
                else
                if (i < MyStringArray.Length - 1)
                {
                    //Do stuff for middle elements.
                    MessageBox.Show("Middle element: " + MyStringArray[i]);
                }
                else
                {
                    //Do stuff for last element.
                    MessageBox.Show("Last element: " + MyStringArray[i]);
                }

            }

This works, but I want to ask whether there is a better way to accomplish the same functionality. Thank your for your time. Saga

Answer 1

Try this code:

//Do stuff for first element.
MessageBox.Show( "First element: " + MyStringArray.First( ) );

for( int i = 1; i < MyStringArray.Length - 1; i++ )
{
    //Do stuff for middle elements.
    MessageBox.Show( "Middle element: " + MyStringArray[i] );
}

//Do stuff for last element.
MessageBox.Show( "Last element: " + MyStringArray.Last( ) );

It assumes that the array is not empty.

An alternative for middle elements:

foreach( var s in MyStringArray.Skip( 1 ).Take( MyStringArray.Length - 2 ) )
{
    //Do stuff for middle elements.
    MessageBox.Show( "Middle element: " + s );
}

In case of modern C# in .NET 6:

foreach( var s in MyStringArray[1..^1] )
{
    //Do stuff for middle elements.
    MessageBox.Show( "Middle element: " + s );
}