utf8 and encoding

Question

I have a sting in unicode is "hao123--我的上网主页", while in utf8 in C++ string is "hao123锛嶏紞鎴戠殑涓婄綉涓婚〉", but I should write it to a file in this format "hao123\uFF0D\uFF0D\u6211\u7684\u4E0A\u7F51\u4E3B\u9875", how can I do it. I know little about this encoding. Can anyone help? thanks!

Answer 1

You seem to mix up UTF-8 and UTF-16 (or possibly UCS-2). UTF-8 encoded characters have a variable length of 1 to 4 bytes. Contrary to this, you seem to want to write UTF-16 or UCS-2 to your files (I am guessing this from the \uxxxx character references in your file output string).

For an overview of these character sets, have a look at Wikipedia's article on UTF-8 and browse from there.

Here's some of the very basic basics (heavily simplified):

• UCS-2 stores all characters as exactly 16 bits. It therefore cannot encode all Unicode characters, only the so-called "Basic Multilingual Plane".

• UTF-16 stores the most frequently-used characters in 16 bits, but some characters must be encoded in 32 bits.

• UTF-8 encodes characters with a variable length of 1 to 4 bytes. Only characters from the original 7-bit ASCII charset are encoded as 1 byte.