I have a set of legacy data that that include individual Unicode chars formed based on struct:
struct LocalGrRec{
wchar_t cBegin;
int x2;
wchar_t cEnd;
in x2;
};
and a typical record looks like this, i.e., includes both long and short Unicode characters
{L'a', 0, L'¥', 3}
I can change the struct to make it easier to handle reading these characters into character variables:
wchar_t c = rec.cBegin;
// or
UTF32Char c = rec.cBegin;
Which one (or perhaps another choice that I don't know of) would make it easier to handle it. Please note that I need to process them as individual chars, but eventually I'll need to include them in an NSString.
What solution gives me the maximum flexibility and minimum pain?
And how would I read that character into a NSString?
Thanks
edit:
I need to compose NSString with it, not the other way around.
With unichar, here's the problem:
unichar c = L'•';
NSLog(#"%c", c); // produces: (") wrong character, presumably the first half of '•'
NSLog(#"%C", c); // produces: (\342\200)
I think you are looking for this method:
[NSString stringWithCharacters:(const unichar*) length:(NSUInteger)];
Just pass it an array of unichars and a length, and it will give you a NSString back
unichar list[3] = {'A', 'B', 'C'};
NSString *listString = [NSString stringWithCharacters:list length:3];
NSLog(#"listString: %#", listString);
Related
I'm working with c in iOS Project I'm trying to convert my string to respected type in c , below code is supposed to send to core Library
typedef uint16_t UniCharT;
static const UniCharT s_learnWord[] = {'H', 'e','l','\0'};
what i have done till now is string is the one what I'm passing
NSString * string = #"Hel";
static const UniCharT *a = (UniCharT *)[string UTF8String];
But it is failing to convert when more than one character , If i pass one character then working fine please let me where i miss, How can i pass like s_learnWord ?
and i tried in google and StackOverFLow none of the duplicates or answers didn't worked for me like this
Convert NSString into char array I'm already doing same way only.
Your question is a little ambiguous as the title says "c type char[]" but your code uses typedef uint16_t UniCharT; which is contradictory.
For any string conversions other than UTF-8, you normally want to use the method getCString:maxLength:encoding:.
As you are using uint16_t, you probably are trying to use UTF-16? You'll want to pass NSUTF16StringEncoding as the encoding constant in that case. (Or possibly NSUTF16BigEndianStringEncoding/NSUTF16LittleEndianStringEncoding)
Something like this should work:
include <stdlib.h>
// ...
NSString * string = #"part";
NSUInteger stringBytes = [string maximumLengthOfBytesUsingEncoding];
stringBytes += sizeof(UniCharT); // make space for \0 termination
UniCharT* convertedString = calloc(1, stringBytes);
[string getCString:(char*)convertedString
maxLength:stringBytes
encoding:NSUTF16StringEncoding];
// now use convertedString, pass it to library etc.
free(convertedString);
I need to find a way to convert an arbitrary character typed by a user into an ASCII representation to be sent to a network service. My current approach is to create a lookup dictionary and send the corresponding code. After creating this dictionary, I see that it is hard to maintain and determine if it is complete:
__asciiKeycodes[#"F1"] = #(112);
__asciiKeycodes[#"F2"] = #(113);
__asciiKeycodes[#"F3"] = #(114);
//...
__asciiKeycodes[#"a"] = #(97);
__asciiKeycodes[#"b"] = #(98);
__asciiKeycodes[#"c"] = #(99);
Is there a better way to get ASCII character code from an arbitrary key typed by a user (using standard 104 keyboard)?
Objective C has base C primitive data types. There is a little trick you can do. You want to set the keyStroke to a char, and then cast it as an int. The default conversion in c from a char to an int is that char's ascii value. Here's a quick example.
char character= 'a';
NSLog("a = %ld", (int)test);
console output = a = 97
To go the other way around, cast an int as a char;
int asciiValue= (int)97;
NSLog("97 = %c", (char)asciiValue);
console output = 97 = a
Alternatively, you can do a direct conversion within initialization of your int or char and store it in a variable.
char asciiToCharOf97 = (char)97; //Stores 'a' in asciiToCharOf97
int charToAsciiOfA = (int)'a'; //Stores 97 in charToAsciiOfA
This seems to work for most keyboard keys, not sure about function keys and return key.
NSString* input = #"abcdefghijklkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890!##$%^&*()_+[]\{}|;':\"\\,./<>?~ ";
for(int i = 0; i<input.length; i ++)
{
NSLog(#"Found (at %i): %i",i , [input characterAtIndex:i]);
}
Use stringWithFormat call and pass the int values.
Now I have a range of unicode numbers, I want to show them in UILabel, I can show them if i hardcode them, but that's too slow, so I want to substitute them with a variable, and then change the variable and get the relevant character.
For example, now I know the unicode is U+095F, I want to show the range of U+095F to U+096f in UILabel, I can do that with hardcode like
NSString *str = [NSString stringWithFormat:#"\u095f"];
but I want to do that like
NSInteger hex = 0x095f;
[NSString stringWithFormat:#"\u%ld", (long)hex];
I can change the hex automatically,just like using #"%ld", (long)hex, so anybody know how to implement that?
You can initialize the string with the a buffer of bytes of the hex (you simply provide its pointer). The point is, and the important thing to notice is that you provide the character encoding to be applied. Specifically you should notice the byte order.
Here's an example:
UInt32 hex = 0x095f;
NSString *unicodeString = [[NSString alloc] initWithBytes:&hex length:sizeof(hex) encoding:NSUTF32LittleEndianStringEncoding];
Note that solutions like using the %C format are fine as long as you use them for 16-bit unicode characters; 32-bit unicode characters like emojis (for example: 0x1f601, 0x1f41a) will not work using simple formatting.
You would have to use
[NSString stringWithFormat:#"%C", (unichar)hex];
or directly declare the unichar (unsigned short) as
unichar uni = 0x095f;
[NSString stringWithFormat:#"%C", uni];
A useful resource might be the String Format Specifiers, which lists %C as
16-bit Unicode character (unichar), printed by NSLog() as an ASCII character, or, if not an ASCII character, in the octal format \ddd or the Unicode hexadecimal format \udddd, where d is a digit.
Like this:
unichar charCode = 0x095f;
NSString *s = [NSString stringWithFormat:#"%C",charCode];
NSLog(#"String = %#",s); //Output:String = य़
I'm trying to grab a character from a UITextField and find the ascii decimal code value for it. I can save the field value into a char variable, but I'm having trouble obtaining the decimal code value. See below code snippet of the problem.
// grabs letter from text field
char dechar = [self.decInput.text characterAtIndex:0]; //trying to input a capital A (for example)
NSLog(#"dechar: %c",dechar); // verifies that dechar holds my intended letter
// below line is where i need help
int dec = sizeof(dechar);
NSLog(#"dec: %d",dec); //this returns a value of 1
// want to pass my char dechar into below 'A' since this returns the proper ASCII decimal code of 65
int decimalCode = 'A';
NSLog(#"value: %d",decimalCode); // this shows 65 as it should
I know going the other way I can just use...
int dec = [self.decInput.text floatValue];
char letter = dec;
NSLog(#"ch = %c",letter); //this returns the correct ASCII letter
any ideas?
Why are you using the sizeof operator?
Simply do:
int dec = dechar;
This will give you 65 for dec assuming that dechar is A.
BTW - you really should change dechar to unichar, not char.
iOS uses unicode, not ASCII. Unicode characters are usually 16 bits, not 8 bits.
Look at using the NSString method characterAtIndex, which returns a unichar. A unichar is a 16 bit integer rather than an 8 bit value, so it can represent a lot more characters.
If you want to get ASCII values from an NSString, you should first convert it to ASCII using the NSString method dataUsingEncoding: NSASCIIStringEncoding, then iterate through the bytes in the date you get back.
Note that ASCII can only represent a tiny fraction of unicode characters though.
I'm using NSXMLParser for parsing XML to my app and having a problem with the encoding type. For example, here is one of the feeds coming in. It looks similar to this"
\U2026Some random text from the xml feed\U2026
I am currently using the encoding type:
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
Which encoding type am I suppose to use for converting \U2026 into a ellipse (...) ??
The answer here is you're screwed. They are using a non-standard encoding for XML, but what if they really want the literal \U2026? Let's say you add a decoder to handle all \UXXXX and \uXXXX encodings. What happens when another feed want the data to be the literal \U2026?
You're first choice and best bet is to get this feed fixed. If they need to encode data, they need to use proper HTML entities or numeric references.
As a fallback, I would isolate the decoder away from the XML parser. Don't create a non-conforming XML parser just because your getting non-conforming data. Have a post processor that would only be run on the offending feed.
If you must have a decoder, then there is more bad news. There is no built in decoder, you will need to find a category online or write one up yourself.
After some poking around, I think Using Objective C/Cocoa to unescape unicode characters, ie \u1234 may work for you.
Alright, heres a snippet of code that should work for any unicode code-point:
NSString *stringByUnescapingUnicodeSymbols(NSString *input)
{
NSMutableString *output = [NSMutableString stringWithCapacity:[input length]];
// get the UTF8 string for this string...
const char *UTF8Str = [input UTF8String];
while (*UTF8Str) {
if (*UTF8Str == '\\' && tolower(*(UTF8Str + 1)) == 'u')
{
// skip the next 2 chars '\' and 'u'
UTF8Str += 2;
// make sure we only read 4 chars
char tmp[5] = { UTF8Str[0], UTF8Str[1], UTF8Str[2], UTF8Str[3], 0 };
long unicode = strtol(tmp, NULL, 16); // remember that Unicode is base 16
[output appendFormat:#"%C", unicode];
// move on with the string (making sure we dont miss the end of the string
for (int i = 0; i < 4; i++) {
if (*UTF8Str == 0)
break;
UTF8Str++;
}
}
else
{
if (*UTF8Str == 0)
break;
[output appendFormat:#"%c", *UTF8Str];
}
UTF8Str++;
}
return output;
}
You should simple replace literal '\U2026' on a quotation, then encode it with NSUTF8StringEncoding encodind to NSData