Exercises in this lecture  previous -- Keyboard shortcut: 'p'        Go to the slide, where this exercise belongs -- Keyboard shortcut: 'u'  

Exercise 10.2
Finding the encoding of a given text file

Make a UTF-8 text file with some words in Danish. Be sure to use plenty of special Danish characters. You may consider to write a simple C# program to create the file. You may also create the text file in another way.

In this exercise you should avoid writing a byte order mark (BOM) in your UTF-8 text file. (A BOM in the UTF-8 text file may short circuit the decoding we are asking for later in the exercise). One way to avoid the BOM is to denote the UTF-8 encoding with new UTF8Encoding(), or equivalently new UTF8Encoding(false). You may want to consult the constructors in class UFT8Encoding for more information.

Now write a C# program which systematically - in a loop - reads the text file six times with the following objects of type Encoding: ISO-8859-1, UTF-7, UTF-8, UTF-16 (Unicode), UTF32, and 7 bits ASCII.

More concretely, I suggest you make a list of six encoding objects. For each encoding, open a TextReader and read the entire file (with ReadToEnd, for instance) with the current encoding. Echo the characters, which you read, to standard output.

You should be able to recognize the correct, matching encoding (UTF-8) when you see it.