What does this code mean

[J. Kevin Robbins]

I found some C# code that works but I don't fully understand it, and that just won't do.

I have a button that will toggle a group of checkboxes on or off all at once. The intent is to save the user the effort of clicking each box individually. This code does the trick.

private void toggleButton_Click(object sender, EventArgs e)
        {
            var checkedBoxes = new[] { groupBox1 }
                                .SelectMany(g => g.Controls.OfType<CheckBox>());

            foreach (var c in checkedBoxes)
                if (c.Checked == true)
                    c.Checked = false;
                else
                    c.Checked = true;
        }

I mostly understand what it's doing except for the "g => g" portion. What is that?

[J. Kevin Robbins]

Replying to myself again. It's a Lambda expression for Linq. There's some information here. I don't fully understand it because I don't use Lambdas in Java, but I guess I have to learn sometime.

[Paul Clapham]

That's what I sort of thought, but I didn't want to post wild guesses about languages which I don't know.

Also, wouldn't it be easier and even clearer to write "toggle a checkbox" like this:

c.Checked = ! c.Checked;

(or however you say "not" in C#)

[J. Kevin Robbins]

I'll try that. I haven't done any C# in about 5 years, so I'm learning it all over again. It's changed a lot. I had to go back to Visual Studio 2010 just so it looked familiar. The 2013 version is a different animal.