ASP.NET 3.5: A Beginner's Guide - www.mustafaof.com

58ASP.NET 3.5: A Beginner’s GuideAll this ASPX file does is to provide a convenient TextBox form for output for a variableto be defined in the C# portion. The C# portion is where you can see definite assignmentat work (or not). First, look at a perfectly well-formed definite assignment for the stringvariable stVar.using System;public partial class DefAssn : System.Web.UI.Page{private string stVar;protected void Page_Load(object sender, EventArgs e){stVar = "Test";Show.Text = stVar;}}When that runs, you will see the value Test appear in the text box window. If youcomment out the line//stVar = "Test";everything still works fine. Nothing appears in the text box window, but the compilerdoesn’t throw an error. However, if you comment out the line//private string stVar;and leave in the statement that provides the variable with the value Test, you will getan error. That’s because the variable has not been declared. If you declared a variable inC# but did not assign it a value (initialize it) prior to using it, you will get an error. So,while it’s an important practice to keep in mind, output to an ASP.NET form is a bit moreforgiving than to a C#-only program that outputs to the System.Console.WriteLineor some similar non-ASP.NET structure.Operators and PunctuatorsC# uses a full set of operators to state the relations between elements in expressions.Likewise, a set of punctuators sets demarcations between different units in statements.Those unfamiliar with operators can think of them as verbs and the different elements