const string inside a function

A snippet from Mricrosoft XNA Education Catalog:

    /// <summary>
    /// Draws the control, using SpriteBatch and SpriteFont.
    /// </summary>
    protected override void Draw()
    {
        const string message = "Hello, World!\n" +
                               "\n" +
                               "I'm an XNA Framework Gr开发者_开发百科aphicsDevice,\n" +
                               "running inside a WinForms application.\n" +
                               "\n" +
                               "This text is drawn using SpriteBatch,\n" +
                               "with a SpriteFont that was loaded\n" +
                               "through the ContentManager.\n" +
                               "\n" +
                               "The pane to my right contains a\n" +
                               "spinning 3D triangle.";

        GraphicsDevice.Clear(Color.CornflowerBlue);

        spriteBatch.Begin();
        spriteBatch.DrawString(font, message, new Vector2(23, 23), Color.White);
        spriteBatch.End();
    }

Draw is called 60 times per second. Is there any performance overhead with assigning message inside the draw? Is it the same as if I move it to static helper class? As far I recall, cost expression is evaluated by C# compiler. What const modifier change here?

A const is evaluated once only. You gain nothing by moving it away into a static variable.

Nope its all optimized for you.