August 20, 2002 - Using the System.Console Class | WebReference

August 20, 2002 - Using the System.Console Class

Yehuda Shiran August 20, 2002
Using the System.Console Class
Tips: August 2002

Yehuda Shiran, Ph.D.
Doc JavaScript

The class System.Console is slightly more powerful than the print statement. Its methods feature display options that are not supported by the print statement. The WriteLine() method mimics the print statement. The Write() method displays a string without appending a newline character. The ReadLine() method reads from the command line, starting from the end of the previous output string, and ending at the end of the line. Having both read and write functionalities enables you to create a dialog with the user.

To use classes from the .NET framework, such as the System.Console above, you need to import the namespace to which the class belongs. Then, when you call a method, you don't need to specify the fully qualified name of the method. Notice again, that the System.Console class is supported only when you compile your JScript .NET code with the jsc compiler and run it from the command line. Using the System.Console class in an ASP.NET page or in Code Behind JScript .NET code will yield a compilation error.

The following JScript .NET script shows how to print messages with the System.Console class: 

import System;
class HelloWorld{
  //constructor
  function HelloWorld() {
    Console.WriteLine("Object Constructed");
  }
  
  function TypeHello() {
    Console.WriteLine("Hello World.");
  }
  
}
var myHelloWorldObj = new HelloWorld();
myHelloWorldObj.TypeHello();
The program defines a class, HelloWorld, with two methods: the constructor HelloWorld() and TypeHello(). Each method prints one string. The constructor prints the message "Object Constructed" when an object of type HelloWorld is constructed. The TypeHello() method prints the message "Hello World". You can compile this program with the jsc compiler. When you run the generated executable (the output of the compiler), you'll see the two print messages.

To learn more about JScript .NET and ASP.NET, go to Column 116, JScript .NET, Part IX: Displaying Information.