I'm trying to get a currency calculator to work, and I've stumbled accross a problem I do not know how to solve.
The problem is that when I normally type into the textfield I can obviously type over the 100.20, the problem arises when I try to do this using buttons.
Whole numbers work fine but as soon as I click on the dot button it put's the dot after the 100.20 so I end up with 100.20. and whatever I click after it.
If I don't use NSNumberFormatter it works fine as well.
Here are the code snippets :
-(IBAction)buttonDigitPressed:(id)sender
{
mainNumber = 100.20;
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle: NSNumberFormatterCurrencyStyle];
mainField.stringValue = [numberFormatter stringFromNumber:[NSNumber numberWithFloat: mainNumber]];
}
if(!userInTheMiddleOfEnteringDecimal)
{
userInTheMiddleOfEnteringDecimal = YES;
mainField.stringValue= [mainField.stringValue stringByAppendingString:#"."];
}
Related
I have a strange problem. It only seems to present on a tester's iPhone 5s.
It works correctly on an iPhone 5, 6 and 6 plus, all running the latest iOS (8.3).
This is the code
-(NSString *) commaString:(double)number
{
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle: NSNumberFormatterDecimalStyle];
[numberFormatter setGroupingSize:3];
[numberFormatter setMaximumSignificantDigits:9];
NSString *numberAsString = [numberFormatter stringFromNumber:[NSNumber numberWithDouble: number]];
return numberAsString;
}
The application is a calculator and is usually presenting correctly like this
It is usually showing correctly like this
but on this iPhone 5s it is showing like this
I thought the setMaximumSignificantDigits would have nipped this in the bud, but it's still showing the same. Could this be some strange localisation thing? I don't think it is as his iPhone 6 it is showing correctly also.
Thanks
Luke
If your goal is to simply have commas every three characters, all you need to do is:
NSNumberFormatter * numberFormatter = [[NSNumberFormatter alloc] init];
numberFormatter.numberStyle = NSNumberFormatterDecimalStyle;
NSNumber * numberFromString = [numberFormatter numberFromString:currentTextWithoutCommas];
NSString * formattedNumberString = [numberFormatter stringFromNumber:numberFromString];
If you're finding that there's an issue with localizing the formatter, then set secondaryGroupingSize to 3. As written in the docs for NSNumberFormatter:
Some locales allow the specification of another grouping size for larger numbers. For example, some locales may represent a number such as 61, 242, 378.46 (as in the United States) as 6,12,42,378.46. In this case, the secondary grouping size (covering the groups of digits furthest from the decimal point) is 2.
Also, you can check out Formatting Numbers on iOSDeveloperTips for a brief, high-level overview.
I'm trying to do things right with input expenses on some items. So, when working on a device using a locale that uses comma separated decimals (the decimal pad automatically sets comma ',' instead of dot '.' for the user to input) I store the value using core data in a double variable converting the text this way:
NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];
[f setMaximumFractionDigits:2];
NSNumber * gasto = [f numberFromString:(((UITextField*) [cell viewWithTag:11]).text)];
destino.nuevaTrans.gasto = [gasto doubleValue];
//destino.nuevaTrans is the managed object, nothing weird there, just storing the decimal value
But when taking the value out of the stored objects and showing them in a table view I'm losing the decimals because of the comma separated locale settings (?). Doing it this way:
etiq = (UILabel*) [cell.contentView viewWithTag:12];
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
etiq.text = [numberFormatter stringFromNumber:#(trans.gasto)];
//debugging console output:
//remmember, trans.gasto is only a double
NSLog(#"a: %f, b: %#", trans.gasto ,[numberFormatter stringFromNumber:#(trans.gasto)]);
The output on the simulator that is using dot '.' locale settings works fine, but when deploying on the device that is using comma ',' settings the NSNumberFormatter doesn't seem to translate it correctly to currency style.
//output on the simulator:
2014-09-07 15:00:47.561 iSpend[3930:60b] a: 2.990000, b: $2.99
//output on the device:
2014-09-07 15:02:40.005 iSpend[1389:60b] a: 2.170000, b: ₡2
So, I could try and hack this thing out... But I'm looking for a better programming practice here. Every suggestion is appreciated! Thanks!
Each Locale determines if it shows cents or just Krona. So, if you want to force it to show digits after the comma, add the line:
[numberFormatter setMinimumFractionDigits:2];
to get two digits after comma.
But the example you show has correct output.
u can try to set separator clearly: [formatter setDecimalSeparator:#"."];
Getting correct localized formatting of numbers to display is easy.
But prompting for a decimal number input from a UITextField is proving tricky.
Even though the decimal keypad may present the comma for European usage instead of the stop, the method handling the input apparently still needs to be locale-savvy.
my research here on S.O. and other places suggests
-(IBAction)buttonPress:(UIButton *)sender
{
NSNumber *firstNumber = #([self.firstField.text floatValue]); // 2 alternative ways
NSNumber *secondNumber = [NSNumber numberWithFloat:[self.secondField.text floatValue]];
.
.
only gives me integers to perform arithmetic with. They aren't floats at all. They have no float value
Supposing this is the only thing the app does, and I immediately do:
.
.
NSNumberFormatter *numberFormat = [[ NSNumberFormatter alloc] init];
[ numberFormat setNumberStyle:NSNumberFormatterDecimalStyle];
[ numberFormat setLocale:[NSLocale currentLocale]];
[ numberFormat setMaximumFractionDigits:2];
NSString *displayString = [ numberFormat stringFromNumber:firstNumber];
self.resultLabel.text = displayString;
}
I am throwing the input back to a label in the ViewController without any further handling to make sure the the decimals aren't hidden by not having a formatter. No Joy. Still in integers.
Obviously the app has to do something in the way of calculation, and since one can't handle NSNumber wrappers directly, I have to resolve it before i do the conversion thing:
double xD = [firstNumber doubleValue];
double yD = [secondNumber doubleValue];
the question is, where is the decimal-ness of the input being lost?
I have no problem with the desktop keyboard and the simulator, but if i set a test device to - say - Polish then that simply won't do.
EDIT:
and here's the result from the answer provided below
// run these 4 methods first, that way you can re-use *numberFormat for the display
NSNumberFormatter *numberFormat = [[ NSNumberFormatter alloc] init];
[ numberFormat setNumberStyle:NSNumberFormatterDecimalStyle];
[ numberFormat setLocale:[NSLocale currentLocale]];
[ numberFormat setMaximumFractionDigits:2];
// here 'tis
NSNumber *firstNumber = [numberFormat numberFromString:self.firstField.text];
// do the same for other input UITextFields
// sh-boom. there you go
You need use longLongValue not longValue to convert NSString to long type. or use NSNumberFormatter->numberFromString:
I have an NSDictionary which consist of multiple key/pair values. One of them consist double value.
NSNumber *goalValue = [info objectForKey:#"goalValue"];
I put breakpoint and I found that goalValue store the normal value that I need.
and just below I convert it to NSSting like
NSString *stringValue=[goalValue stringValue];
and this stringValue store very strange value.
Guys please help me. I am totally puzzled, I did goggle but nothing change. Please help me. Thanks in advance.
The method stringValue will convert the NSNumber to string by internally calling descriptionWithLocale: with locale as nil and this method in turn will call initWithFormat:locale:,
From Apple docs,
To obtain the string representation, this method invokes NSString’s initWithFormat:locale: method, supplying the format based on the type the NSNumber object was created with:
So format specifier used for double is %0.16g(i.e. 16 digit precision) hence the value 98.09999999999999
I'd suggest using NSNumberFormatter,
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
[numberFormatter setMaximumFractionDigits:2]; //2 decimal places, change this as required.
NSString *string = [numberFormatter stringFromNumber:goalValue];
Hope that helps!
To prevent this behavior, I suggest using NSDecimalNumber (also this is from my experience best format when dealing with very precise amounts)
NSDecimalNumber *doubleDecimal = [[NSDecimalNumber alloc] initWithDouble:[info objectForKey:#"goalValue"]];
for two digits formatting, use numberFormatter
NSNumberFormatter * nf = [[NSNumberFormatter alloc] init];
[nf setMinimumFractionDigits:2];
[nf setMaximumFractionDigits:2];
NSString *stringValue = [nf stringFromNumber:doubleDecimal]
Its showing the rounded value so you can round the value to single digit using NSNumberFormatter.
NSNumberFormatter *fomatter = [[NSNumberFormatter alloc] init];
[fomatter setMaximumSignificantDigits:2];
NSString *stringValue=[fomatter stringFromNumber:goalValue];
Not sure if this is possible, but for my app I would like to get a locale based string that describes a number.
For example, if I had the number 10,000,000.
In english, I would expect the phrase "Ten Million". However, in Hindi, it would be One crore. Is there any properties in NSNumberFormatter, or NSLocale that could help me with this?
I have checked the docs (NSNumberFormatter, NSLocale), and havent found what I'm looking for yet. Obviously I could write some code to handle these two cases, but I'd like a way that could work for any locale.
Edit: Thanks to leo for the answer! Here is a small snippet of code that will get anyone looking for the same thing started:
NSNumberFormatter formatter = [[NSNumberFormatter alloc] init];
[self.formatter setNumberStyle:NSNumberFormatterSpellOutStyle];
NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:#"hi_hi"];
[self.formatter setLocale:locale];
NSNumber * myNumber = [NSNumber numberWithInt:10000];
self.numberLabel.text = [self.formatter stringFromNumber:myNumber];
What you are looking for is the NSNumberFormatterSpellOutStyle style.
NSString* spelledOutString = [NSNumberFormatter localizedStringFromNumber:#10000000 numberStyle:NSNumberFormatterSpellOutStyle];