I'm parsing data from a JSON webservice and adding it to the database so when I insert an int, I have to convert it to NSNumber in this way it's working fine: 24521478
NSString *telephone = [NSString stringWithFormat:#"%#",[user objectForKey:#"telephone"]];
int telephoneInt = [telephone intValue];
NSNumber *telephoneNumber = [NSNumber numberWithInt:telephoneInt];
patient.telephone = telephoneNumber;
but when I want to display it and convert the NSNumber to NSString I'm getting wrong numbers: -30197
NSString *telephoneString = [NSString stringWithFormat:#"%d", [user.telephone intValue], nil];
labelTelephone.text =telephoneString ;
Can someone explain this?
NSNumber comes with dedicated methods for each data type.If you want to convert NSNumber to NSString use:
NSString *telephoneString = [user.telephone stringValue];
The issue may coming because of the data type you used for the variable patient.telephone
If you have control over the web service, then you should return the telephone number as string in the JSON
Reasons
if the telephone number begin with zero then the NSNumber will remove that zero as it has no value (ex: 00123456789 will be 123456789 which will wrong data)
You will not be able to display the telephone number is a user friendly way by adding "+" and "-" (ex: +123-456-789)
You really should make the json return the number as string if you have a control over that
Related
I currently receive emojis in a payload in the following format:
\\U0001F6A3\\U0000200D\\U00002640\\U0000FE0F
which represents "🚣♀️"
However, if I try to display this, it only shows the string above (escaped with 1 less ), not the emoji e.g.
NSString *emoji = payload[#"emoji"];
NSLog(#"%#", emoji) then displays as \U0001F6A3\U0000200D\U00002640\U0000FE0F
It's as if the unicode escape it not being recognised. How can I get the string above to show as an emoji?
Please assume that the format the data is received in from the server cannot be changed.
UPDATE
I found another way to do it, but I think the answer by Albert posted below is better. I am only posting this for completeness and reference:
NSArray *emojiArray = [unicodeString componentsSeparatedByString:#"\\U"];
NSString *transformedString = #"";
for (NSInteger i = 0; i < [emojiArray count]; i++) {
NSString *code = emojiArray[i];
if ([code length] == 0) continue;
NSScanner *hexScan = [NSScanner scannerWithString:code];
unsigned int hexNum;
[hexScan scanHexInt:&hexNum];
UTF32Char inputChar = hexNum;
NSString *res = [[NSString alloc] initWithBytes:&inputChar length:4 encoding:NSUTF32LittleEndianStringEncoding];
transformedString = [transformedString stringByAppendingString:res];
}
Remove the excess backslash then convert with a reverse string transform stringByApplyingTransform. The transform must use key "Any-Hex" for emojis.
NSString *payloadString = #"\\U0001F6A3\\U0000200D\\U00002640\\U0000FE0F";
NSString *unescapedPayloadString = [payloadString stringByReplacingOccurrencesOfString:#"\\\\" withString:#"\\"];
NSString *transformedString = [unescapedPayloadString stringByApplyingTransform:#"Any-Hex" reverse:YES];
NSLog(#"%#", transformedString);//logs "🚣♀️"
I investigated this, and it seems you may not be receiving what you say you are receiving. If you see \U0001F6A3\U0000200D\U00002640\U0000FE0F in your NSLog, chances are you are actually receiving \\U0001F6A3\\U0000200D\\U00002640\\U0000FE0F at your end instead. I tried using a variable
NSString *toDecode = #"\U0001F6A3\U0000200D\U00002640\U0000FE0F";
self.tv.text = toDecode;
And in textview it is displaying the emoji fine.
So you got to fix that first and then it will display well.
I have an id which holds an int. I need to cast it to an NSString and append it to another NSString.
I've trued different approaches but I have different type of errors. My confusion is that int is not an object type.
My code is:
NSString *str = [dict objectForKey:[NSNumber numberWithLongLong:ID]];
In this case I have (int) 1000.
When I try to append it to NSString I get an exception.
How can I properly cast from an id, which holds int, to NSString ?
NSString *str = [[dict objectForKey:[NSNumber numberWithLongLong:ID]] stringValue];
This question already has answers here:
Split an NSString to access one particular piece
(7 answers)
Closed 9 years ago.
I want to filter string after character '='. For eg if 8+9=17 My output should be 17. I can filter character before '=' using NSScanner, how to do its reverse??? I need a efficient way to do this without using componentsSeparatedByString or creating an array
Everyone seems to like to use componentsSeparatedByString but it is quite inefficient when you just want one part of a string.
Try this:
NSString *str = #"8+9=17";
NSRange equalRange = [str rangeOfString:#"=" options:NSBackwardsSearch];
if (equalRange.location != NSNotFound) {
NSString *result = [str substringFromIndex:equalRange.location + equalRange.length];
NSLog(#"The result = %#", result);
} else {
NSLog(#"There is no = in the string");
}
Update:
Note - for this specific example, the difference in efficiencies is negligible if it is only being done once.
But in general, using componentsSeparatedByString: is going to scan the entire string looking for every occurrence of the delimiter. It then creates an array with all of the substrings. This is great when you need most of those substrings.
When you only need one part of a larger string, this is very wasteful. There is no need to scan the entire string. There is no need to create an array. There is no need to get all of the other substrings.
NSArray * array = [string componentsSeparatedByString:#"="];
if (array)
{
NSString * desiredString = (NSString *)[array lastObject]; //or whichever the index
}
else
{
NSLog(#""); //report error - = not found. Of array could somehow be not created.
}
NOTE:
Though this is very popular splitting solution, it is only worth trying whenever every substring separated by separator string is required. rmaddy's answer suggest better mechanism whenever the need is only to get small part of the string. Use that instead of this approach whenever only small part of the string is required.
Try to use this one
NSArray *arr = [string componentsSeparatedByString:#"="];
if (arr.count > 0)
{
NSString * firstString = [arr objectAtIndex:0];
NSString * secondString = [arr objectAtIndex:1];
NSLog(#"First String %#",firstString);
NSLog(#"Second String %#",secondString);
}
Output
First String 8+9
Second String 17
Use this:
NSString *a =#"4+6=10";
NSLog(#"%#",[a componentsSeparatedByString:#"="])
;
Log: Practice[7582:11303] (
"4+6",
10
)
I'm getting a JSON string back from a web service I'm using, one of the items is a float, which is formatted like this: "1.2".
But I actually want to make it show like a time number, so like this: "01:20".
What would be the easiest way of doing this?
I thought about converting the float to a string and then splitting it into 2 pieces
timeValue = [NSString stringWithFormat:#"%.2f", timeValue];
NSArray *tmpArr = [timeValue componentsSeparatedByString:#"."];
NSString *tmpFirst = (NSString *)[tmpArr objectAtIndex:0];
NSString *tmpSecond = (NSString *)[tmpArr objectAtIndex:0];
But somehow when I convert it, it returns me a negative number
NSLog(#"timeValue: %#", timeValue);
timeValue: -1.99
I think the problem is in this line.
timeValue = [NSString stringWithFormat:#"%.2f", timeValue];
I think timeValue is of type NSString if not then why are you using same variable twice.
It should be like
timeValueString = [NSString stringWithFormat:#"%.2f", timeValueFloat];
My code looks like this
NSNumber *inputToNumber = [NSNumber numberWithFloat:[textField.text floatValue]];
the value from the textfield is actually a telephone number. It's stored in NSNumber as an annoying (2.0)78966e+08
How can I just get NSNumber to store it as 0207896608?
I think that the basic idea to store a phone number into a NSNumber is flawed:
how do you discriminate between numbers with or without leading 0 ?
how do you store phone numbers from foreign countries ?
I would use NSString in place of NSNumber.
Just because it's called a number doesn't mean a "telephone number" is a number in the same sense that "5" or "pi" are.
Either you should treat a telephone number as a string, or you should create a TelephoneNumber model class to represent each one.
Consider that there are places in the world where numbers don't have leading 0's and where a number with a leading 0 is not the same as the same number without a leading 0.
05843924 != 5843924
So stop being lazy with that NSNumber hacks and build your own phone-number class.
Scientific notation is used in may computer languages as the default output of very large (or very small) numbers. If you want the number to be output as a decimal, you need to specify the output format (the implementation varies by language.)
Also, julesjacobs is correct. You should not use FLOAT for a phone number as it is subject to binary rounding errors. Using INT or STRING will save you lots of headaches.
If you need to be able to deal with it as numbers maybe you should break it up into its parts, and store each part as an integer.
01112223333
country code 0
area code 111
prefix 222
number 3333
Or you could store the whole thing as a string if you don't need to manipulate it.
Are you storing a phone number in a float? You should consider using an integer or string. Perhaps:
NSNumber *inputToNumber = [NSNumber numberWithInt:[textField.text intValue]];
Hey Guys what do you think of this, It seems to full-fill my purposes. Only UK at the moment so will worry about localization when I get a chance.
I use this to get to store the number
NSNumber *inputToNumber = [NSNumber numberWithLongLong:(long long)[[textField.text stringByReplacingOccurrencesOfString:#" " withString:#""] longLongValue]];
And this method formats my telephone number and takes care of the preceeding 0 mentioned.
-(NSString *)phoneNumberString:(NSNumber *)phoneNumber {
//Add a zero because NSNumber won't save a preceeding zero
NSString *telephoneString = [[NSString alloc] initWithFormat:#"0%#", [phoneNumber stringValue]];
if (telephoneString.length >= 4) {
NSString *firstPart = [[NSString alloc] initWithString: [telephoneString substringToIndex:4]];
NSString *secondPart = [[NSString alloc] initWithString: [telephoneString substringFromIndex:4]];
//Add the two parts together with a space inbetween
NSString *formattedTelephoneString = [NSString stringWithFormat:#"%# %#", firstPart, secondPart];
//send it back to the cellForRow TableCell Method
[firstPart release];
[secondPart release];
[telephoneString release];
return formattedTelephoneString;
}
else {
return telephoneString;
}
}
Thanks for all the comments. I'm gonna mark the answer as whoever suggested NSString as I fear I will revert to using NSString for this instead of my above workaround.