NSMutableString conversion errors - ios

I have the following code and I'm banging my head against a wall trying to figure out what's producing the errors.
NSMutableString *entry = (#"%# (%#): %#",translatedHeadword,adlerNumber,meaning);
entry = [entry replaceOccurrencesOfString:#"<br/>" withString:#" " options:NSCaseInsensitiveSearch range:NSMakeRange(0, entry.length)];
The second line is giving two errors: Implicit conversion of 'NSUInteger' toNSMutableStringis disallowed with ARC and Incompatible integer to pointer conversion assigning to NSMutableString from NSUInteger. But translatedHeadword, adlerNumber, and meaning are all NSStrings. adlerNumber contains characters representing numbers, but it's still a string.
What am I doing wrong?

The syntax (#"%#", foo) does not produce string formatting. You need to use [NSMutableString stringWithFormat:] to do string formatting.
Also, replaceOccurrencesOfString:... returns the number of changed things and mutates the string itself. So, it's complaining about the assignment entry = ... because the right-hand side is the NSUInteger returned by replaceOccurencesOfString:....

Related

Way to detect character that takes up more than one index spot in an NSString?

I'm wondering, is there a way to detect a character that takes up more than 1 index spot in an NSString? (like an emoji). I'm trying to implement a custom text view and when the user pushes delete, I need to know if I should delete only the previous one index spot or more.
Actually NSString use UTF-16.So it is quite difficult to work with characters which takes two UTF-16 charater(unichar) or more.But you can do with rangeOfComposedCharacterSequenceAtIndexto get range and than delete.
First find the last character index from string
NSUInteger lastCharIndex = [str length] - 1;
Than get the range of last character
NSRange lastCharRange = [str rangeOfComposedCharacterSequenceAtIndex: lastCharIndex];
Than delete with range from character (If it is of two UTF-16 than it deletes UTF-16)
deletedLastCharString = [str substringToIndex: lastCharRange.location];
You can use this method with any type of characters which takes any number of unichar
For one you could transform the string to a sequence of characters using [myString UTF8String] and you can then check if the character has its first bit set to one or zero. If its one then this is a UTF8 character and you can then check how many bytes are there to this character. Details about UTF8 can be found on Wikipedia - UTF8. Here is a simple example:
NSString *string = #"ČTest";
const char *str = [string UTF8String];
NSMutableString *ASCIIStr = [NSMutableString string];
for (int i = 0; i < strlen(str); ++i)
if (!(str[i] & 128))
[ASCIIStr appendFormat:#"%c", str[i]];
NSLog(#"%#", ASCIIStr); //Should contain only ASCII characters

Xcode - UTF-8 String Encoding

I have a strange problem encoding my String
For example:
NSString *str = #"\u0e09\u0e31\u0e19\u0e23\u0e31\u0e01\u0e04\u0e38\u0e13";
NSString *utf = [str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog("utf: %#", utf);
This worked perfectly in log
utf: ฉันรักคุณ
But, when I try using my string that I parsed from JSON with the same string:
//str is string parse from JSON
NSString *str = [spaces stringByReplacingOccurrencesOfString:#"U" withString:#"u"];
NSLog("str: %#, str);
NSString *utf = [str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog("utf: %#", utf);
This didn't work in log
str: \u0e09\u0e31\u0e19\u0e23\u0e31\u0e01\u0e04\u0e38\u0e13
utf: \u0e09\u0e31\u0e19\u0e23\u0e31\u0e01\u0e04\u0e38\u0e13
I have been finding the answer for hours but still have no clue
Any would be very much appreciated! Thanks!
The string returned by JSON is actually different - it contains escaped backslashes (for each "\" you see when printing out the JSON string, what it actually contains is #"\").
In contrast, your manually created string already consists of "ฉันรักคุณ" from the beginning. You do not insert backslash characters - instead, #"\u0e09" (et. al.) is a single code point.
You could replace this line
NSString *utf = [str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
with this line
NSString *utf = str;
and your example output would not change. The stringByReplacingPercentEscapesUsingEncoding: refers to a different kind of escaping. See here about percent encoding.
What you need to actually do, is parse the string for string representations of unicode code points. Here is a link to one potential solution: Using Objective C/Cocoa to unescape unicode characters. However, I would advise you to check out the JSON library you are using (if you are using one) - it's likely that they provide some way to handle this for you transparently. E.g. JSONkit does.

Converting int to NSString

I thought I had nailed converting an int to and NSString a while back, but each time I run my code, the program gets to the following lines and crashes. Can anyone see what I'm doing wrong?
NSString *rssiString = (int)self.selectedBeacon.rssi;
UnitySendMessage("Foo", "RSSIValue", [rssiString UTF8String] );
These lines should take the rssi value (Which is an NSInt) convert it to a string, then pass it to my unity object in a format it can read.
What am I doing wrong?
NSString *rssiString = [NSString stringWithFormat:#"%d", self.selectedBeacon.rssi];
UPDATE: it is important to remember there is no such thing as NSInt. In my snippet I assumed that you meant NSInteger.
If you use 32-bit environment, use this
NSString *rssiString = [NSString stringWithFormat:#"%d", self.selectedBeacon.rssi];
But you cann't use this in 64-bit environment, Because it will give below warning.
Values of type 'NSInteger' should not be used as format arguments; add
an explicit cast to 'long'
So use below code, But below will give warning in 32-bit environment.
NSString *rssiString = [NSString stringWithFormat:#"%ld", self.selectedBeacon.rssi];
If you want to code for both(32-bit & 64-bit) in one line, use below code. Just casting.
NSString *rssiString = [NSString stringWithFormat:#"%ld", (long)self.selectedBeacon.rssi];
I'd like to provide a sweet way to do this job:
//For any numbers.
int iValue;
NSString *sValue = [#(iValue) stringValue];
//Even more concise!
NSString *sValue = #(iValue).stringValue;
NSString *rssiString = [self.selectedBeacon.rssi stringValue];
For simple conversions of basic number values, you can use a technique called casting. A cast forces a value to perform a conversion based on strict rules established for the C language. Most of the rules dictate how conversions between numeric types (e.g., long and short versions of int and float types) are to behave during such conversions.
Specify a cast by placing the desired output data type in parentheses before the original value. For example, the following changes an int to a float:
float myValueAsFloat = (float)myValueAsInt;
One of the rules that could impact you is that when a float or double is cast to an int, the numbers to the right of the decimal (and the decimal) are stripped off. No rounding occurs. You can see how casting works for yourself in Workbench by modifying the runMyCode: method as follows:
- (IBAction)runMyCode:(id)sender {
double a = 12345.6789;
int b = (int)a;
float c = (float)b;
NSLog(#"\ndouble = %f\nint of double = %d\nfloat of int = %f", a, b, c);
}
the console reveals the following log result:
double = 12345.678900
int of double = 12345
float of int = 12345.000000
original link is http://answers.oreilly.com/topic/2508-how-to-convert-objective-c-data-types-within-ios-4-sdk/
If self.selectedBeacon.rssi is an int, and it appears you're interested in providing a char * string to the UnitySendMessage API, you could skip the trip through NSString:
char rssiString[19];
sprintf(rssiString, "%d", self.selectedBeacon.rssi);
UnitySendMessage("Foo", "RSSIValue", rssiString );

Poor compiler warnings

how to get rid of the compiler warning in XCode 5.1
in Stringtable is of course a string with a format specifier (updated: now in front of code)
"fmtDetail" = "Count: %d";
int number = 0;
//Compiler warning: Data argument not used by format string
NSString *text = [NSString stringWithFormat:NSLocalizedString(#"fmtDetail", nil), number];
//this gets no warning
NSString *fmtDetail = NSLocalizedString(#"fmtDetail", nil);
NSString *text2 = [NSString stringWithFormat:fmtDetail, number];
It is not the compiler warning that is poor - you should correct your code.
There seems to be an %d (or similar) missing in the #"fmDetail".
Or you should get rid of the number argument - that is not used.
Depends on what you are actually trying to do...
NSString *text = [NSString stringWithFormat:NSLocalizedString(#"fmtDetail%d", nil), number];
NSString *text = [NSString stringWithFormat:NSLocalizedString(#"fmtDetail %d", nil), number];
NSString *text = [NSString stringWithString:NSLocalizedString(#"fmtDetail", nil)];
Second note: this #"fmtDetail%d" should match the key in the plist dictionary (translated strings). It could also be simly #"theDeatils" - the string that returned from your plist is the one that should actually hold formatting data for the string.
Why would one want to use the %d in the key? Because NSLocalizedString returns the key as the result if it doesn't find string with appropriate key.
EDIT: MartinR found the real reason for why this warning appears. Just a note that might be useful: since localizing strings usually means translation into many languages (duh) you might need to use numbered placeholders - not all languages share the same basic sentence structure.
This seems to be not a bug, but a new feature of the compiler that comes with Xcode 5.1 (beta). It expects now that in
[NSString stringWithFormat:NSLocalizedString(key, ...), arguments... ]
the key itself is a valid format for the given arguments.
(In other words, the key uses the same format specifiers as its value from the strings file).
For example:
// Source code:
[NSString stringWithFormat:NSLocalizedString(#"Count = %d", nil), number]
// Localizable.strings:
"Count = %d" = "Die Anzahl ist %d";
This is an advantage because the compiler can now check that the number and types
of the format specifiers match the actual arguments even with localizable format
strings. That was not possible before (as far as I know).
For example, this will cause a warning in Xcode 5.1 beta, but not in Xcode 5.0.2:
[NSString stringWithFormat:NSLocalizedString(#"fmtDetail %f", nil), 13];
// warning: format specifies type 'double' but the argument has type 'int' [-Wformat]
(And as #rokjarc already had pointed out, using a valid format string as key makes
sense anyway, because NSLocalizedString() returns the key if no matching string
is found in the Localizable.strings file.)

Extract text from a NSString using regular expressions

I have a NSString in this format:
"Key1-Value1,Key2-Value2,Key3-Value3,..."
I need only keys (with a space after every comma):
Key1, Key2, Key3, etc.
I thought to create an array of components from the string using the comma as separator, and after, for every component, extract all characters since the "-"; then I'd serialize the array elements. But I fear this could be very heavy about performances.
Do you know a way to do this using regular expressions?
The regex will greatly depend on the data you are using. For example if the key or value is allowed to be all numbers, or allowed to contain space and punctuation, you would need to modify the regex. For your current example however this will work.
NSString *example = #"Key1-Value1,Key2-Value2,Key3-Value3,...";
NSString *result = [example stringByReplacingOccurrencesOfString:#"(\\w+)-(\\w+),?"
withString:#"$1, "
options:NSRegularExpressionSearch
range:NSMakeRange(0, [example length])];
result = [result stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#", "]];
NSLog(#"%#", result);

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