How to convert large UTF-8 strings into ASCII?

Question

I need to convert large UTF-8 strings into ASCII. It should be reversible, and ideally a quick/lightweight algorithm.

How can I do this? I need the source

Answer 1

If the string is encoded as UTF-8, it's not a string any more. It's binary data, and if you want to represent the binary data as ASCII, you have to format it into a string that can be represented using the limited ASCII character set.

One way is to use base-64 encoding (example in C#):

string original = "asdf";
// encode the string into UTF-8 data:
byte[] encodedUtf8 = Encoding.UTF8.GetBytes(original);
// format the data into base-64:
string base64 = Convert.ToBase64String(encodedUtf8);

If you want the string encoded as ASCII data:

// encode the base-64 string into ASCII data:
byte[] encodedAscii = Encoding.ASCII.GetBytes(base64);