I am new in programming. I have string NSString *string = #"\U0420\U043e\U0437\U044b"; and after each slash('\') i need put another slash to get string like this #"\\U0420\\U043e\\U0437\\U044b"
I am new to programming and objective-c. please help.
My original answer was:
Use [NSString stringByReplacingOccurrencesOfString:withString:] (reference).
NSString *string = #"\U0420\U043e\U0437\U044b";
NSString *converted = [string stringByReplacingOccurrencesOfString:#"\\"
withString:#"\\\\\\"];
However I now don't think that's right given the \ characters won't actually exist in string; instead the compiler will convert each of those sequences into a unicode character. You will need to encode string as this:
NSString *string = #"\\U0420\\U043e\\U0437\\U044b";
In order to use the above code. I cannot see any alternative to this.
Further Update: Often when I've come across questions like this there is a confusion between string literals and string data. In your question those \ characters won't appear as the compiler will have converted them into unicode characters (\Uxxx is a unicode escape sequence for a single character). However if you provided a string like that at runtime (say read from a text file) then those \ characters will exist and you can use the code above.
Related
Sorry for maybe a newbie question.
For various reasons I am stuck with a peculiar string that looks like this:
NSString *myString = #"A\\314\\212A\\314\\210O\\314\\210.jpg";
Can I in some ninja-way remove the double \\ and force NSString understand that the string is Uniencoded and should be read like this
NSString *myString = #"A\314\212A\314\210O\314\210.jpg"; // Displays ÅÄÖ as expected
I have tried different strategies tried to replace all slashes ("\"), but as soon as I add a ("\") NSString adds another one to escape the first one. And I get stuck here...
Is it possible to prevent NSString to escape my string?
UPDATE
I am aware this is a special case. Reading the output from a terminal program which reads files on the users drive. Via a NSTask I am capturing the output to into a NSString for parsing and splitting it into an array. It works great as long as there are no non-ascii characters. HFS+ is encoding non-ascii characters with slightly different Unicode called NFD.
When I am capturing the reponse, the ÅÄÖ are already encoded inside qoutes like this:
file.jpg
file2.jpg
"A\314\212A\314\210O\314\210.jpg"
When I create a NSString and with the captured reponse, it gets escaped by NSString a second time.
A\\314\\212A\\314\\210O\\314\\210.jpg
I am aware that this is not the optimal, but right now I have no control over what the terminal program is outputting. Usually when a NSString is created with this NFD encoding, Objectiv-C takes care of the encoding/decoding for you. But since I have a string with mixed and double escaped content, I have a hard way of creating it and make NSString to understand that the content is encoded with this encoding.
Basically I would like to to this:
decodedString = [output stringByReplacingOccurrencesOfString:#"\\\\"
withString:#"\\"];
But behind the scenes NSString is always escaping \ with another \ for you so I would like a way to create "raw" strings with out NSString interfering.
Have tried various ways to try enforing Unicode encoding on NSString but it all boils down to NSString is always capturing and escaping \.
Any tips och points appreciated!
I did not find any way around this other than go the other way around and change the output from the terminal program not to encode it this way.
Im wondering how to convert
NSString = "\xC4"; ....
to real NSString represented in normal format
Fundamentally related to xcode UTF-8 literals. Of course, it is ambiguous what you actually mean by "\xC4" - without an encoding specified, it means nothing.
If you mean the character whose Unicode code point is 0x00C4 then I would think (though I haven't tested) that this will do what you want.
NSString *s = #"\u00C4";
First are you sure you have \xC4 in your string? Consider:
NSString *one = #"\xC4\x80";
NSString *two = #"\\xC4\\x80";
NSLog(#"%# | %#", one, two);
This will output:
Ā | \xC4\x80
If you are certain your string contains the four characters \xC4 are you sure it is UTF-8 encoded as ASCII? Above you will see I added \x80, this is because \xC4 is not valid UTF-8, it is the first byte of a two-byte sequence. Maybe you have only shown a sample of your input and the second byte is present, if not you do not have UTF-8 encoded as ASCII.
If you are certain it is UTF-8 encoded as ASCII you will have to convert it yourself. It might seem the Cocoa string encoding methods would handle it, especially as what you appear to have is a string as it might be written in Objective-C source code. Unfortunately the obvious encoding, NSNonLossyAsciiStringEncoding only handles octal and unicode escapes, not the hexadecimal escapes in your string.
You can use any algorithm you like to convert it. One choice would be a simple finite state machine which scans the input a byte at a time and recognises the four byte sequence: \, x, hex-digit, hex-digit; and combines the two hex-digits into a single byte. NSString is not the best choice for byte-at-time string processing, you may be better off converting to C strings, e.g.:
// sample input, all characters should be ASCII
NSString *input = #"\\xC4\\x80";
// obtain a C string containing the ASCII characters
const char *cInput = [input cStringUsingEncoding:NSASCIIStringEncoding];
// allocate a buffer of the correct length for the result
char cOutput[strlen(c2a)+1];
// call your function to decode the hexadecimal escapes
convertAsciiEncodedUTF8(cInput, cOutput);
// create a NSString from the result
NSString *output = [NSString stringWithCString:cOutput encoding:NSUTF8StringEncoding];
You just need to write the finite state machine, or other algorithm, for convertAsciiEncodedUTF8.
(If you write an algorithm and it fails ask another question showing your code, somebody will probably help you. But don't expect someone to write it for you.)
HTH
I have an NSString instance (let's called it myString) containing the following UTF-8 unicode character: \xc2\x96 ( that is the long dash seen in, e.g., MS Word ).
When printing the NSString to the console using NSLog and the %# format specifier, the character is replaced by an upside-down question mark indicating that something is wrong - and when using it as text in a table cell, the unicode character simply appears as blank space ( not the empty string - a blank space ).
To solve this, I would like to replace the \xc2\x96 unicode character with a "normal" dash - at first I thought this should be a 10 sec. task but after some research I have not yet found the "right way" to do this and this is where I would like your help.
What I have tried:
When I print myString in hex like this NSLog(#"%x", myString) I get the hex value: 96 for the unicode character representing the unicode character \xc2\x96.
Using this information I have made the following implementation to replace it with its "normal" dash equivalent:
for(int index = 0; index < [myString length]; index++)
{
NSLog(#"Hex:'%x' Char:'%c'", [myString characterAtIndex:index],[myString characterAtIndex:index]);
if([[NSString stringWithFormat:#"%x", [myString characterAtIndex:index]] isEqualToString:#"96"])
myString = [myString stringByReplacingCharactersInRange:NSMakeRange(index, 1) withString:#"-"];
}
... it works, but my eyes don't like it, and I would like to know if this can be done in much more cleaner and "right" way? E.g. like C#'s String.Replace(char,char) which supports unicode characters .
So to wrap up:
I'm looking for the "right way" to replace unicode chars in a string - I have done some research, but apparently, there is only methods available that replaces occurrences of a given NSString with another NSString.
I have read the following:
https://stackoverflow.com/a/5223737/700926
https://stackoverflow.com/a/5217703/700926
https://stackoverflow.com/a/714009/700926
https://stackoverflow.com/a/668254/700926
https://stackoverflow.com/a/2039396/700926
... but all of them explains how to replace a given NSString with another NSString and do not cover how specific unicode characters ( in particular double byte ) can be replaced.
You can make your string mutable (i. e. use an NSMutableString instead of an NSString). Also, the call to [[NSString stringWithFormat:#"%x", character] isEqualToString:#"96"] is as inefficient as possible - why not simply if (character == 0x96)? All in all, try
NSString *longDash = #"\xc2\x96";
[string replaceOccurrencesOfString:longDash withString:#"-"];
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
unicode escapes in objective-c
I have a LATIN1 string.
Artîsté
When I json_encode it, it escapes some chars and converts it to single byte UTF8.
Art\u00eest\u00e9
If I just json_decode it, I believe it is decoding in UTF8
Artîsté
In order to get my original string back, I have to call utf8_decode
Artîsté
Is there a way to handle this conversion in objective-c?
You might be looking for this:
NSString *string = (some string with non-ASCII characters in it);
char const *string_as_latin1 = [string cStringUsingEncoding:NSISOLatin1StringEncoding];
or possibly this:
NSData *data_latin1 = [string dataUsingEncoding:NSISOLatin1StringEncoding allowLossyConversion:YES];
I have a LATIN1 string.
I don't think you do. Assuming you are talking about PHP, json_encode() only accepts UTF-8 strings, and bails out if it hits a non-UTF-8 high-byte sequence:
json_encode("Art\xeest\xe9")
"Art"
json_encode("Art\xc3\xaest\xc3\xa9")
"Art\u00eest\u00e9"
I think you had a proper UTF-8 string to start with, then you encoded and decoded it to get the exact same UTF-8 string back. But then you're displaying it or processing it in another step you haven't shown us, that treats your string as if it were Latin-1.
This String is base64 encoded string:
NSString *string=#"ë§ë ë¼ì´";
This is not show the orginal string:
NSLog(#"String is %#",[string cStringUsingEncoding:NSMacOSRomanStringEncoding]);
That's not a Base64-encoded string. There are a couple other things going on with your code, too:
You can't include literal non-ASCII characters inside a string constant; rather, you have to use the bytes that make up the character, prefixed with \x; or in the case of Unicode, you can use the Unicode code point, prefixed with \u. So your string should look something like NSString *string = #"\x91\xa4\x91 \x91\x93";. But...
The characters ¼ and ´ aren't part of the MacRoman encoding, so you'll have trouble using them. Are you sure you want a MacRoman string, rather than a Unicode string? Not many applications use MacRoman anymore, anyway.
cStringUsingEncoding: returns a C string, which should be printed with %s, not %#, since it's not an Objective-C object.
That said, your code will sort of work with:
// Using MacRoman encoding in string constant
NSString *s = #"\x91\xa4\x91 \x91\x93";
NSLog(#"%s", [s cStringUsingEncoding:NSMacOSRomanStringEncoding]);
I say "sort of work" because, again, you can't represent that code in MacRoman.
That would be because Mac OS Roman is nothing like base-64 encoding. Base-64 encoding is a further encoding applied the bytes that represent the original string. If you want to see the original string, you will first need to base-64 decode the bytestring and then figure out the original string encoding in order to interpret it.