How to trim off symbols from NSNumber? - nsnumber

Im making an iOS app to do with currency. My app receives the value of maybe: $4. This value the app receives is put into an NSNumber. The trouble is the value actualy has a $ in it. How do I trim out the $ in the NSNumber? Or would I be better of putting it into an NSString?

Use NSNumberFormatter:
// set up your number formatter
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
// get a string that you'll be converting to a NSNumber
NSString *myNumberString = [NSString stringWithFormat:#"$4"]
// convert then print to the console
NSNumber *myNumber = [numberFormatter numberFromString:myNumberString];
NSLog(#"myNumber: %#", myNumber);
This should accomplish what you're looking to do. myNumberString will need to be altered to contain whatever string you're receiving.
NSNumberFormatter Documentation: https://developer.apple.com/library/ios/#documentation/Cocoa/Reference/Foundation/Classes/NSNumberFormatter_Class/Reference/Reference.html

Related

Convert NSString to few NSIntegers

I have getting data from plist to NSString, in result I see something like this "{{1848,594},{154,176}}". What is the best way to convert every single number to separate NSInteger?
NSString *frame = [myPlistKey objectForKey:#"frame"];
How to convert frame to 4 separate integers?
In this specific case, it looks like you are trying to parse the string representation of an NSRect, in which case you can just use NSRectFromString() from the Foundation framework.
Edit:
Since you are not much specific, I will try to cover your situation. If i count with the fact you have NSString *frame filled with {{1848,594},{154,176}}:
NSString *stringWithoutLeftBracket = [frame
stringByReplacingOccurrencesOfString:#"{" withString:#""];
NSString *stringWithoutRightBracket = [stringWithoutLeftBracket
stringByReplacingOccurrencesOfString:#"}" withString:#""];
NSArray *frameArray = [stringWithoutRightBracket componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#","]];
Then you can access objects with indexes like:
NSInteger integer = [[frameArray objectAtIndex:0] integerValue];
But also you could use a for loop like this:
for (NSInteger integer in frameArray) {
// Do something
}
In my opinion you have a string made from rect, means you could convert it.

Setting UILabel to Same value as NSString

I have searched for hours on this one subject and still have not been able to solve my problem. I have a string value that I need converted into a label. In my code I save the NSString and then make sure I am getting a value with the NSLog (which I DO). Then is where I am having problems. I try to set the label value equal to the nesting but when I run its NSLog I get (null). So my question is how may I make my label equal the value of my string? Thank you so much!
NSString *linkString = self.product[#"link"];
NSLog(#"%#", linkString);
linkLabel.text = linkString;
NSLog(#"%#", linkLabel);
Your NSString will never be equal to your UILabel.
on the other hand, your UILabel's text property which is an NSString will be
try to change the code to this
NSString *linkString = self.product[#"link"];
NSLog(#"%#", linkString);
linkLabel.text = linkString;
NSLog(#"%#", linkLabel.text);
All I changed was linkLabel in your NSLog to linkLabel.text
Assuming like you said that linkString has a value, the second log should output the same as the first log.
EDIT: I saw your comment above, there is no need for a duplicate definition of the label as an #property and above that in the h file.
Are you sure that
NSString *linkString = self.product[#"link"];
works? Try this:
NSString *linkString = #"Test";
and use this for logging:
NSLog(#"%#", linkLabel.text);
Did you forget to hook up the linkLabel in your XIB? Is the value of linkLabel not nil?
What does NSLog(#"%#", linkLabel); print out?

Issues using NSNumberFormatter?

I'm trying to make a label to show the temperature, with a maximum of 3 digits for temperatures over a 100, but I don't want any decimals...
NSString *longtempstring = [tmp description];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setMaximumFractionDigits:3];
[formatter setMinimumFractionDigits:0];
NSString *shorttempstring = [formatter stringForObjectValue:[NSString stringWithString:longtempstring]];
The code above always returns (null)
Any ideas?
You are getting nil because the object you are passing to stringForObjectValue: is not of the type expected.
First of all, don't use stringForObjectValue:. That is a member of the parent class, NSFormatter. NSNumberFormatter has more specific methods that avoid confusion of object types like numberFromString: and stringFromNumber:.
Second, NSNumberFormatter is used to go from number to formatted string or formatted string to number. Not directly from formatted string to formatted string. You will need to use one number formatter to read your original string and produce a number and another to produce a new shorter formatted string from that number.
Of course, you might be able to make the first step (from long string to number) easier by using NSScanner or by taking a substring of your long string (cutting out everything except for the number itself) and then using the NSString method integerValue or doubleValue. A regular expression could also be used to extract the number from the first (longer) string.
The long and short of it is, this is a two step process. The first step (getting a number) can be accomplished any number of ways and a NSNumberFormatter might not be the easiest way. The second step (getting a new shorter string) is what NSNumberFormatter is perfect for.
I fixed it by converting the NSString to an NSNumber and only pulling the integer value from the string, thus removing any decimals.
NSString *longtempstring = [tmp description];
NSNumber *tempintegervalue = [NSNumber numberWithInteger:[longtempstring integerValue]];
NSString *shorttempstring = [tempintegervalue stringValue];
NSString *longtempstring = [tmp description];
What is the value of longtempstring here? Is it even a number?
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setMaximumFractionDigits:3];
[formatter setMinimumFractionDigits:0];
Why do you set maximum fraction digits to 3 if you say that you don't want any fraction digits? Fraction digits are what is "after the dot" and you say you don't want any decimals. If you don't want any decimals, minimum and maximum must be set to 0.
NSString *shorttempstring = [formatter stringForObjectValue:[NSString stringWithString:longtempstring]];
First of all, why are you copying the string? [NSString stringWithString:...] creates a new string that is a copy of the string you provide as argument. Strings are immutable, there is no need to copy them, they won't be modified. If you are afraid that a NSString may in fact be a NSMutableString, after all that is a subclass of NSString and you want to copy it, just copy it by calling [aString copy]. copy is a very smart method here. If the NSString is in fact a mutable string, it will really copy it, so you get an immutable copy. If it is not a mutable string, though, copy just returns the same string with a retain count increased by one (so in that case copy behaves exactly like retain). However, in your case copying makes no sense whatsoever.
And second, what makes you believe, that you can feed a string into a NSNumberFormater? It is called NSNumberFormater because it formats objects of type NSNumber. How is a NSString a NSNumber? It is not called NSStringFormater. If you feed an object of the wrong class to a formater, it will return nil, that's how this method is documented.
If your longtempstring contains a number with fraction, e.g. 12.345, then the correct code would look like this:
NSString * longtempstring = [tmp description];
NSNumberFormatter * formatter = [[NSNumberFormatter alloc] init];
[formatter setMaximumFractionDigits:0];
[formatter setMinimumFractionDigits:0];
NSNumber * tempnumber = [NSNumber numberWithDouble:[longtempstring doubleValue]];
NSString * shorttempstring = [formatter stringForObjectValue:tempnumber];
However, if all you want to do is cut off the decimals, that is a horrible way to do it. This can be done much more effective:
double d;
NSString * longtempstring;
NSString * shorttempstring;
longtempstring = #"12.345";
d = [longtempstring doubleValue];
shorttempstring = [NSString stringWithFormat:#"%d", (int)d];
This is much shorter, needs less memory, and is at least three times faster. If you want to round the number (that means everything with a fraction .5 and above is rounded to the next higher value), just round it:
d = round([longtempstring doubleValue]);

Attaching multiple uitextfields to an email

I have multiple UITextFields and I want to attach them to an in app email. I can get one of them appear but not the rest. Here is what I am using.
MFMailComposeViewController *composer = [[MFMailComposeViewController alloc] init];
[composer setMailComposeDelegate:self];
[composer setSubject:#"My Subject"];
[composer setMessageBody:AddNotesTextField.text isHTML:YES];
[self presentModalViewController:composer animated:YES];
[composer release];
Thank you
You got it right already for the body using:
[composer setMessageBody:AddNotesTextField.text isHTML:YES];
So just repeat the procedure with the other fields like so:
[composer setSubject:mySubjectTextField.text];
Or if you are asking how to use the input from multiple text fields into the body of the email, you simply have to use NSString's stringWithFormat:
[composer setMessageBody:[NSString stringWithFormat:#"you can place static %# text in between %# these variables",AddNotesTextField.text,someOtherField.text] isHTML:YES];
In string with format, you escape the default string to add a string using "%#" for every instance where you want to insert some other string. Then after the original string ends you enter the names of the input strings separated by commas. [NSString stringWithFormat:#"%#%#",x,y]

Easiest way to format a number with thousand separators to an NSString according to the Locale

I can't seem to find an easy way to do it. The exact thing I need is:
[NSString stringWithFormat:#"%d doodads", n];
Where n is an int. So for 1234 I'd want this string (under my locale):
#"1,234 doodads"
Thanks.
For 10.6 this works:
NSNumberFormatter* numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setFormatterBehavior: NSNumberFormatterBehavior10_4];
[numberFormatter setNumberStyle: NSNumberFormatterDecimalStyle];
NSString *numberString = [numberFormatter stringFromNumber: [NSNumber numberWithInteger: i]];
And it properly handles localization.
I have recently discovered this one-liner:
[#1234567 descriptionWithLocale:[NSLocale currentLocale]]; // 1,234,567
Or in Swift 2:
1234567.descriptionWithLocale(NSLocale.currentLocale()) // 1,234,567
Swift 3/4:
(1234567 as NSNumber).description(withLocale: Locale.current)
Formatted per the question:
[#(n) descriptionWithLocale:[NSLocale currentLocale]];
Formatted without Objective-C literals:
[[NSNumber numberWithInt:n] descriptionWithLocale:[NSLocale currentLocale]];
This is the solution I was looking for when I asked the question. Available since iOS 2.0 and OS X 10.0, documented to return a string version of the number formatted as per the locale provided. stringValue is even documented to use this method but passing nil.
Seeing as it is my question and this fits my answer best, I am tempted to change the tick, but it seems cruel. Update I changed the tick, this answer is the answer.
The below doesn't address the locale, but it is a better way (in my opinion) of setting the thousand separator on the number formatter.
NSNumberFormatter *numberFormat = [[[NSNumberFormatter alloc] init] autorelease];
numberFormat.usesGroupingSeparator = YES;
numberFormat.groupingSeparator = #",";
numberFormat.groupingSize = 3;
Todd Ransom answered this perfectly.
I would just like to add (in a separate comment, so I can show some nicely formatted code), that if you plan to do this regularly, it's worth creating an NSString helper class.
So, create yourself an NSStringHelper.h containing this:
#import <Foundation/Foundation.h>
#interface NSString (NSStringHelper)
+(NSString*)formatWithThousandSeparator:(NSInteger)number;
#end
..and an NSStringHelper.m file containing this:
#import "NSStringHelper.h"
#implementation NSString (NSStringHelper)
+(NSString*)formatWithThousandSeparator:(NSInteger)number
{
// Format a number with thousand seperators, eg: "12,345"
NSNumberFormatter* numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setFormatterBehavior: NSNumberFormatterBehavior10_4];
[numberFormatter setNumberStyle: NSNumberFormatterDecimalStyle];
NSString *result = [numberFormatter stringFromNumber:[NSNumber numberWithInteger:number]];
return result;
}
#end
This gives you the perfect way to reuse this code in future projects.
#import "NSStringHelper.h"
NSInteger numOfUsers = 12345;
NSString* strNumberOfUsers = [NSString formatWithThousandSeparator:numOfUsers];
Cool, hey ?
Again, apologies for reposting Todd's answer (which was exactly what I was looking for !), but this is a great way to solve the problem, and have it ready to be used in your future XCode projects.
Use an NSNumberFormatter.

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