Insert \u2265 into a C# string

Question

I have a data source that contains a \u2265, which is the greater or equal sign appearing as a single character just like this: ≥

However when the data reaches my application it comes in as \\u2265.

I'm not concerned right now with why the extra \ is occurring.

Instead I just want to be able to convert the \\u2265 to a \u2265 inside my application.

I have tried various string manipulations such as these, and they either had syntax problems, or simply didn't work:

disp = dataSource.Replace('\\', '\');  
disp = dataSource.Replace("\\", "\");

and

int x = dataSource.IndexOf("\\u");
disp = dataSource.Substring(0, x) + dataSource.Substring(x+1);

Part of the problem with the Substring technique is that \\ is being seen as a single character.

Your two screenshots show the exact same code - so how are you seeing different results? Also, how is the data getting to your application? (Basically, we'll need more context in order to help.) — Jon Skeet, Dec 13 '18 at 17:09
\ is an escape character, so when you see `"\\"` there's actually only 1 \ in the string. — user247702, Dec 13 '18 at 17:09
I am not sure I am following, just adding the char to the string should work. [See here](https://dotnetfiddle.net/f0v8BU) — maccettura, Dec 13 '18 at 17:09
I think the second screen shot shows `disp` after `disp = dataSource` whereas the first one shows `disp` right before that. — MikeH, Dec 13 '18 at 17:11
It looks like the screenshots are confusing the issue. I'm going to get rid of them. — dev1998, Dec 13 '18 at 17:11
@dev1998 Look at my comment and the link. Your code should work 100% as expected. If its not, you need to give us a [MCVE] — maccettura, Dec 13 '18 at 17:13
@maccettura the problem is that his dataSource is bringing it in as a string, not a char — MikeH, Dec 13 '18 at 17:14
@maccettura, The problem is that the incoming data is where the problem is, but I can't easily do anything about that right now. I'm just trying to recognize the \\u and fix that so it is a \u. — dev1998, Dec 13 '18 at 17:16
@MikeH Yeah but OP's original screenshot shows `disp` being completely overriden with the value of `dataSource`. OP's problem is _very_ unclear — maccettura, Dec 13 '18 at 17:16
What is _"a data source that contains a `\u2265`"_? When you read it, do you see a string like _"x \u2265 y"_, with the backslash doubled up when you look at it in the debugger? If so, that's not the same as _"x ≥ y"_. The latter has a ≥ character in it, the former has that character represented as a six character string. Have you tried substituting "≥" for "\u2265"? — Flydog57, Dec 13 '18 at 17:16
@dev1998 you simply can't convert `\\u2265` into `≥` by replacing ``\\`` with ``\``.. Check this https://stackoverflow.com/questions/9738282/replace-unicode-escape-sequences-in-a-string — laika, Dec 13 '18 at 17:17

score 3 · Accepted Answer · edited Dec 14 '18 at 11:51

3

The problem is that your data source has the \u2265 as a string and is not treating it as a char. If you replace the string version with a char version you'll get what you need.

data = data.Replace("\\u2265", '\u2265'.ToString());

The reason for the ToString() is so that we can use the appropriate overload for Replace.

Simpler version supplied by @Flydog57:

data = data.Replace("\\u2265", "\u2265");

General version inspired by @Jimi:

Regex r = new Regex(@"\\u[0-9]{4}");
var matches = r.Matches(data);
var uniqueMatches = matches
      .OfType<Match>()
      .Select(m => m.Value)
      .Distinct();

foreach (var m in uniqueMatches)
{
  data = data.Replace(m,Regex.Unescape(m));
}

edited Dec 14 '18 at 11:51

user247702

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answered Dec 13 '18 at 17:16

MikeH

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Not sure why someone voted this down. This is what I'd guess (from the little information in the original post) is the issue (well, with an edit to make it compile). +1 from me. – Flydog57 Dec 13 '18 at 17:17
2

Instead of `'\u2265'.ToString()`, you could have just said `"\u2265"`. – Flydog57 Dec 13 '18 at 17:19
I'll try this, stand by. – dev1998 Dec 13 '18 at 17:19
Dont know how I missed the `ToString()`, my bad – maccettura Dec 13 '18 at 17:19
@Flydog57 You're correct with the `"\u2265"`. I'll update – MikeH Dec 13 '18 at 17:21
I can see now that my question was not clear enough. This answer certainly does work, but I actually need something more generic. It is possible that some code other than 2265 will be in the data. – dev1998 Dec 13 '18 at 17:26
@dev1998 Sure, as long as there's a general form you can search and replace. Will it always be of the form `"\\uxxxx"`? – MikeH Dec 13 '18 at 17:28
@MikeH yes \\uxxxx will be used. – dev1998 Dec 13 '18 at 17:29
@MikeH, Thanks for your help. – dev1998 Dec 13 '18 at 17:31
@dev1998 Jimi's answer has it. – MikeH Dec 13 '18 at 17:41
@dev1998 I've added a version that should avoid unexpected "unescaping" – MikeH Dec 13 '18 at 17:45

score 3 · Answer 2 · answered Dec 13 '18 at 17:40

3

Another option, of more general use (but not always applicable, it might interfere with the string content) is to unescape the string using Regex.Unescape():

string myString = "\\u2265" + "20180426";
myString = Regex.Unescape(myString);

will print

≥20180426

answered Dec 13 '18 at 17:40

Jimi

29,621
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Nice! The last piece to the puzzle is the `Unescape`. I couldn't come up with it! – MikeH Dec 13 '18 at 17:44
@MikeH Yes, but it could mess with the string content. If the content is just what is shown here, it can work. – Jimi Dec 13 '18 at 17:47
1

I think updated my version (shamelessly borrowing from you) avoids the mess. +1 from me though. – MikeH Dec 13 '18 at 17:48
The next problem I had was to decide between your answer and @MikeH as being correct. I decided to go with MikeH because of the way it looked for the unique matches. However both answers were up voted by me. I appreciate all the help. – dev1998 Dec 13 '18 at 18:04
Absolutely. @MikeH Made all the *hard work*. Anyway, this is your question, you don't need to justify your choices :) – Jimi Dec 13 '18 at 18:07

Insert \u2265 into a C# string

2 Answers2