Single speacl quote char in C# String.

Question

Hi All I have a question. Could you please let me know the reason for the following two characters? 1) ' = 8217 - Ascii value binary value 10000000011001 2) ' = 39 - Ascii value binary value 100111 A) Why do programmers delete non-ascii or on-printable characters from a string when we can store and print them? we can store (1) as string1 = Doesn't matter; and also print it. we can store (2) as string2 = Doesn't matter; and also print it. B) If (1) gets stored in a string what format does the .net framework system stores it internally? C) if (1) gets compared with other string what format does the system represent the string in before actual comparison? Could anyone please let me know at the earlier? Thank you so much!

Vulpes · Answer

Character 8217 is what is known as the 'punctuation apostrophe'. It serves as both an apostrophe and closing single quotation mark. Whilst it is the preferred character to use for an apostrophe according to the Unicode standard character 39 (the original ASCII apostrophe) is normally used instead as it's available directly from most keyboards. For more info on apostrophes see: http://en.wikipedia.org/wiki/Apostrophe Strings in .NET are essentially a sequence of unicode characters i.e. each character requires 2 bytes of storage. For extended ASCII characters (up to character 255) one byte is always zero. When strings are compared the unicode values of corresponding characters are compared with each other. If programmers are working in a single byte encoding such as ASCII then non-ASCII characters are usually represented by a question mark (chacracter 63). They are seldom ignored altogether in my experience. It is possible to switch between unicode strings and byte arrays representing single byte encodings using the System.Text.Encoding class: http://msdn.microsoft.com/en-us/library/system.text.encoding.aspx