macOS NSString to char*

[sujithkrishnan]

Hi all.

In my Iphone application, i successfully converted NSString to const char* using
const char* cString = [nsStringObject cStringUsingEncoding:ASCIIEncoding];
and i made use of the printf("%s",cString) to display it in console...
But its printing only the first letter, not the entire string..
(I am a little weak in pointers)
Is it because of any null termination problems??
Kindly help me in resolving this..

Also i want to know "Why NSLog(nsStringObject) is not printing anything in console?

I wnat to see my NSException reason (which is of NSString type)

 

[Sbrocket]

NSLog() prints messages to the debugger window in Xcode as of Beta 5 or 6, not the Console logs.

 

[lee1210]

I can't say immediately what might cause this, but that encoding doesn't look valid.

The list of NSStringEncoding types is here:
http://developer.apple.com/document...g.html#//apple_ref/doc/c_ref/NSStringEncoding

I would expect an error if you used an encoding that is not supported, but maybe ASCIIEncoding is set to some value that matches up to a Unicode or other 16-bit encoding, and so the result you are getting would be:

cString[0] = 'M'
cString[1] = '\0'
cString[2] = 'y'
cString[3] = '\0'
cString[4] = ' '
cString[5] = '\0'
cString[6] = 't'
cString[7] = '\0'
cString[8] = 'e'
cString[9] = '\0'
cString[10] = 's'
cString[11] = '\0'
cString[12] = 't'
cString[13] = '\0'

for an NSString containing "My test". Try UTF8String instead of cStringUsingEncoding, or pick a different encoding from that list that you know is 8-bit per character. Otherwise, you cannot use any of the standard C functions that deal with "character strings", due to the reliance on a null terminator, etc.

-Lee

 

[Krevnik]

My question is: are you really using the value ASCIIEncoding as the encoding type? If so, it isn't what you want. You want NSASCIIEncoding instead.

 

[white89gt]

I believe you'll have better luck converting you NSString to UTF8. I don't have my Cocoa book in front of me, but I'll post up what it recommends when I get home this afternoon.

 

[gnasher729]

Hi all.

In my Iphone application, i successfully converted NSString to const char* using
const char* cString = [nsStringObject cStringUsingEncoding:ASCIIEncoding];

There is no identfier "ASCIIEncoding" in any header file, so this shouldn't compile. Do you have a variable named "ASCIIEncoding" anywhere? Or did you use for example kCFStringEncodingASCII (which is very wrong for NSString)?

 

[white89gt]

I just checked my Cocoa Programming for Mac OS X book and Hillegas recommends the following way to convert NSStrings to c style strings.

NSString *foo = @"your text here";
const char *bar = [foo UTF8String];

 

[TeeJayEm]

I just checked my Cocoa Programming for Mac OS X book and Hillegas recommends the following way to convert NSStrings to c style strings.

NSString *foo = @"your text here";
const char *bar = [foo UTF8String];

I can confirm, you should be using UTF8String

 

[lee1210]

I think the OPs question has been answered many times over, it just happens to be 3:15am in Bangalore at the moment. Hopefully we've led them in the right direction.

-Lee

 

[sujithkrishnan]

My question is: are you really using the value ASCIIEncoding as the encoding type? If so, it isn't what you want. You want NSASCIIEncoding instead.

Sorry...
yeah.. i made use of NSASCIIEncoding...

okie.. now i will try wityh UTF8Encoding .

Thanks to all....

I think the OPs question has been answered many times over, it just happens to be 3:15am in Bangalore at the moment. Hopefully we've led them in the right direction.

-Lee

Thank You Lee..

I got it....

 

[gnasher729]

Sorry...
yeah.. i made use of NSASCIIEncoding...

okie.. now i will try wityh UTF8Encoding .

You can't be using NSASCIIEncoding because there is no NSASCIIEncoding. By asking for help and being too careless to give actual correct information you are just wasting everyone's time.

 

[sujithkrishnan]

You can't be using NSASCIIEncoding because there is no NSASCIIEncoding. By asking for help and being too careless to give actual correct information you are just wasting everyone's time.

i meant ASCIIEncoding
Sorry for the mistake..

 

[valexa]

i meant ASCIIEncoding
Sorry for the mistake..

he means NSASCIIStringEncoding .. he's very confused

 

[gnasher729]

Hi all.

In my Iphone application, i successfully converted NSString to const char* using
const char* cString = [nsStringObject cStringUsingEncoding:ASCIIEncoding];
and i made use of the printf("%s",cString) to display it in console...
But its printing only the first letter, not the entire string..
(I am a little weak in pointers)
Is it because of any null termination problems??
Kindly help me in resolving this..

Also i want to know "Why NSLog(nsStringObject) is not printing anything in console?

I wnat to see my NSException reason (which is of NSString type)

Why are you using ASCII encoding? This will prevent your code from working with lots and lots of possible data. If you need a char*, I would really recommend that you go for UTF8.