You'll learn more about creating methods in a bit. Program. cs. Program. Its file extension is . When you build the program from a command prompt, the dotnet build tool will build all of the files that end in . Although it's a small program, there are a number of important bits of syntax in it that you should understand. First, remember that C# is case- sensitive, so keywords won't work unless they're lowercase, and other named elements within the source code must exactly match the case of the element being referenced. The first line of the program isusing System. Experts Exchange > Questions > HOw to run a program on AS/400 using.NET/C#? Want to Advertise Here? OK I need to run a program on AS/400 from.NET. I have all the information such as . This code is helpful to run ruby program using command prompt in C# and Vb.NET. Run Ruby Program using C# and Vb.net. Sometimes you want to run program in C# or Vb.NET.
The using statement is a programmer convenience. It allows us to refer to elements that exist within the listed namespace (in this case, System) without prefixing them with the namespace name. A namespace is a way of organizing programming constructs. They're similar to folders or directories in your file system. You don't have to use them, but they make it much easier to find and organize things. The reason this program includes the System namespace is that the Console type (used to print . If the using statement were removed, the Console. Write. Line statement would need to include the namespace, becoming System. Console. Write. Line. Using statements must end with a semicolon (; ). In C#, most statements that aren't defining a scope end with a semicolon. After the using statements, the code declares its namespace: namespace Console. Application. Again, it's a good idea to use namespaces to keep larger codebases organized. In this case, the Console. Application namespace has only one element in it (the Program class), but this would grow as the program grew in complexity. Namespaces use curly braces (. Namespaces are optional; you'll frequently see they're omitted from the small samples shown in this tutorial. Inside the namespace's scope (defined by its curly braces), a class called . The public keyword describes the class's accessibility level. This defines how the class may be accessed by other parts of the program, and public means there are no restrictions to its access. The class keyword is used to define classes in C#, one of the primary constructs used to define types you will work with. C# is a strongly typed language, meaning that most of the time you'll need to explicitly define a type in your source code before it can be referenced from a program. Inside the class's scope, a method called . Like classes, methods can have accessibility modifiers, too. In this case, public means there are no limitations on access to this method. Next, the static keyword marks this method as global and associated with the type it's defined on, not a particular instance of that type. You'll learn more about this distinction in later lessons. The void keyword indicates that this method doesn't return a value. The method is named Main. Finally, inside of parentheses (( and ), the method defines any parameters it requires. In this case, the method has no parameters, but a command line program might accept arguments by specifying a parameter of type string array. This parameter is typically defined as string. Arguments correspond to parameters. A method defines the parameters it requires; when calling a method, the values passed to its parameters are referred to as arguments. Like namespaces and classes, methods have scope defined by curly braces. A class can contain many methods, which are one kind of member of that class. Within the method's scope, there is one line: Console. Write. Line(. It's worth noting that this code does not create an instance of the Console type - it is simply calling the Write. Line method on the type directly. This tells you that Write. Line, like the Main method in this program, is declared as a static method. This means that any part of the application that calls this method will be calling the same method, doing the same thing. The program won't, for instance, open several different console windows and write to them separately. Every call to Console. Write. Line is going to write to the same console window. Inside of the parentheses, the program is passing in . This is an argument, and will be used by the Write. Line method internally. C# defines a number of built- in types, one of which is a string. A string is a series of text characters. In this case, the program is passing the string . At the end of the line, the statement ends with a semicolon. After the Console. Write. Line statement, there are three closing curly braces . These close the scopes for the Main method, the Program class, and the Console. Application namespace, respectively. Note that the program uses indentation to make it easy to see which elements of the code belong to which scope. This is a good practice to follow, and will make it much easier for you (or others) to quickly read and understand the code you write. Troubleshooting. Especially if you create the initial program by hand, rather than from a template, it can be easy to make small mistakes that result in errors when you compile the application. You'll find a list of common errors in the troubleshooting lesson. Next Steps. Modify your console application to display a different message. Go ahead and intentionally add some mistakes to your program, so you can see what kinds of error messages you get from the compiler. The more familiar you are with these messages, and what causes them, the better you'll be at diagnosing problems in your programs that you didn't intend to add! In this tutorial, you'll learn how to use Excel's built- in styles, how to modify styles, and how to create your own. You'll also learn how to use your custo.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
December 2016
Categories |