UIKeyboardTypeDecimalPad - change comma to dot - iphone

I use this method to show keyboard with decimal separator
myTextField.keyboardType=UIKeyboardTypeDecimalPad;
How can I change comma to dot separator?
I have a Finnish locale. With comma, decimals doesn't work on my app.
-(IBAction)calculate {
float x = ([paino.text floatValue]) / ([pituus.text floatValue]) *10000;
label.text = [[NSString alloc] initWithFormat:#"%0.02f", x];
}

OK so you edit a text field using a numeric keyboard, which is dependent on the current locale, and thus get a text representation of a number, which is dependendt on the current locale, too. After editing has finished you read it and want to transform into a number.
To convert you would use NSNumberFormatter like this:
NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
You can setup the formatter as you will, setting locale (!), limits, formatting, decimal/grouping separator, number of decimal digits etc. Then you just use it:
float number = [nf numberFromString: field.text];
And that's all! Now you have the number even if the text includes comma, provided you let both: keyboard and formatter, to have the same format, same style - i.e. probably just let current locale be used all over the place.
EDIT
this is a currency formatter, that can convert between string and number for currencies:
NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[nf setNumberStyle: NSNumberFormatterCurrencyStyle];
[nf setRoundingMode: NSNumberFormatterRoundHalfUp];
[nf setMaximumFractionDigits: 2]
this is a percentage formatter with 4 decimal places:
NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[nf setNumberStyle: NSNumberFormatterPercentStyle];
[nf setRoundingMode: NSNumberFormatterRoundHalfUp];
[nf setMaximumFractionDigits: 4];
both in the current locale.
As you see you can define the style, digits, rounding behaviour and much more, depending on numbers you are trying to enter. For more details (it is really a lot you can do with the NSNumberFormatter) you should read Apple docs, it would go beyond the scope of SO answer to describe it all.
In your case, provided that paino and pituus are also UITextFields:
-(IBAction)calculate {
NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[nf setRoundingMode: NSNumberFormatterRoundHalfUp];
[nf setMaximumFractionDigits: 2];
float npaino = [[nf numberFromString: paino.text] floatValue];
float npituus = [[nf numberFromString: pituus.text] floatValue];
float x = npaino] / npituus *10000;
label.text = [nf stringFromNumber: [NSNumber numberWithFloat: x]];
[nf release];
}
Now to avoid creating the formatter in each calculation you could make it an instance variable, since you need only one for those conversions.

Easyer that way:
[[yourField text] stringByReplacingOccurrencesOfString:#"," withString:#"."]
It will work in all ways and languages.
In your code, it will be:
-(IBAction)calculate {
float fPaino = [[paino.text stringByReplacingOccurrencesOfString:#"," withString:#"."] floatValue];
float x = fPaino / ([pituus.text floatValue]) *10000;
label.text = [[NSString alloc] initWithFormat:#"%0.02f", x];
}
Something else: are you sure to need an "alloc" for the result? As the label.text contains already its retain/release, you can simply make a [NSString stringWithFormat:#"%0.02f", x]

Related

Display an integer with a comma: 30000 --> 30,000

How do I display an integer within a UILabel with a comma?
Like this:
30000 --> 30,000
My English is not that good so I did not know what to search for.
Thank you for your answers.
Use the NSNumberFormatter and do just few things as :
NSInteger integerValue=30000;
NSNumberFormatter *numberFormatterComma = [NSNumberFormatter new];
[numberFormatterComma setNumberStyle:NSNumberFormatterDecimalStyle];
NSString *formatted = [numberFormatterComma stringFromNumber:[NSNumber numberWithInteger:integerValue]];
NSLog(#"--> %#",formatted);
Now you can put the formatted string to your label.
You want to look at NSNumberFormatter
Here is an example
self.numberFormat = [[NSNumberFormatter alloc] init];
//set up formatter for display text
[self.numberFormat setNumberStyle:NSNumberFormatterDecimalStyle];
[self.numberFormat setRoundingMode:NSNumberFormatterRoundFloor];
[self.numberFormat setMinimumFractionDigits:0];
[self.numberFormat setMinimumIntegerDigits:1];
[self.numberFormat setMaximumFractionDigits:24];
[self.numberFormat setMaximumSignificantDigits:24];
NSString* formattedText =
[self.numberFormat stringFromNumber:[self.numberFormat numberFromString:rawString]];
Take care not to alloc/init them often, they are quite heavy objects. Best to create once and keep in a property for reuse. If you are making OSX apps (as opposed to ios) you get formatting objects in Interface Builder also, you can drag them around and set their parameters in the attributes inspector.
// Comma seperated numeric conversion
-(NSString*)convertNumericIntoCommaSeperatedValue:(NSString*)string{
NSNumberFormatter *frmtr = [[NSNumberFormatter alloc] init];
[frmtr setGroupingSize:3];
[frmtr setGroupingSeparator:#","];
[frmtr setUsesGroupingSeparator:YES];
NSString *commaSeperatedString = [frmtr stringFromNumber:[NSNumber numberWithLongLong:[string longLongValue]]];
[frmtr release],frmtr=nil;
return commaSeperatedString;
}

NSNumberFormatter's multiplier rounds down instead of showing fraction

I have configured an NSNumberFormatter to convert amounts that are stored as cents in an NSDictionary to euro's. Because they're stored as cents, I have set the formatter's multiplier to [NSNumber numberWithDouble:0.01]. However, when I try to display 304 euro cents as euro's I get € 3,00.
This leads me to believe that the multiplier is doing integer division instead of double division.
NSFormatter configuration
/**
Returns an NSNumberFormatter that can be used to display currency in euro's (as determined in The Netherlands).
*/
+ (NSNumberFormatter *)euroCurrencyFormatter
{
static NSNumberFormatter *numberFormatter = nil;
#synchronized(self) {
if (!numberFormatter) {
numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[numberFormatter setMultiplier:[NSNumber numberWithDouble:0.01]];
NSLocale *nlLocale = [[NSLocale alloc] initWithLocaleIdentifier:#"nl_NL"];
[numberFormatter setLocale:nlLocale];
[nlLocale release];
}
}
return numberFormatter;
}
Calling the NSFormatter
cell.detailTextLabel.text = [[NSNumberFormatter euroCurrencyFormatter] stringFromNumber:[breakdown valueForKey:#"VatAmount"]]; // The VAT amount would be 304.
Result
€ 3,00
How can I stop errounous behaviour?
Try this code.
cell.detailTextLabel.text = [[NSNumberFormatter euroCurrencyFormatter] stringFromNumber:[NSNumber numberWithDouble:[[breakdown valueForKey:#"VatAmount"] doubleValue]]]; // The VAT amount would be 304.
As if you pass VAT as a integer you will get the number always in int format.
See the "Configuring Rounding Behavior" of the NSNumberFormatter reference.

Formatting float values

This is probably a stupid question but anyway.
I wan the number I set on my label to be formated nicely like this 20,000,000 .
How do I do this ?
For now I've set the number of decimal points to 0 so I just get the whole number without any places.
[NSString stringWithFormat:#"%.0f", slider.value];
you can use the following formatter:
-(void)setCurrencyFormat
{
NSNumberFormatter *CurrencyFormat = [[NSNumberFormatter alloc] init];
[CurrencyFormat setNumberStyle:NSNumberFormatterCurrencyStyle];
label.text= [CurrencyFormat stringFromNumber:[NSNumber numberWithDouble:billAmountInDouble]];
NSString *st1=[NSString stringWithFormat:#"%#",[CurrencyFormat stringFromNumber:[NSNumber numberWithDouble:individualTaxInDouble]]];
label.text=st1;
}
Check out the docs for NSNumberFormatter - you can do pretty much everything with that.

Showing formatted digits in textField iphone application

I am taking data from XMl file, the distance in xml is like
<distance>13.472987570222 km</distance>
Now i want to show just two digits after . operator. i.e i want to show in textField like 13.47 km. i have saved this distance digits in NSString *distance;
Thanks
float theDistance = [distance floatValue];
NSString *roundedDistance = [NSString stringWithFormat:#"%.2f",theDistance];
That will round to 2dp. :)
You can use very powerful class NSNumberFormatter:
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setPositiveFormat:#"##0.## km"];
[numberFormatter setNegativeFormat:#"##0.## km"];
NSNumber *number = [NSNumber numberWithDouble:[distance doubleValue]];
NSString *formattedString = [numberFormatter stringFromNumber:number];
For more info read here
Strikes me you should really be converting the xml string into a float or some other such appropriate type and then using a format specifier when displaying the value.

Custom floating decimal points

label.text = [NSString stringWithFormat:#"%.2f",final];
The above statement displays the float value available in the variable "final" with two digits after decimal point.
I want to display number of decimals in depending upon the number i have give to a integer variable like this
label.text = [NSString stringWithFormat:#"%.if",j,final]
Here j is integer variable. Whatever the number i have taken for j that many decimals it should display. I need proper syntax to display the above statement.
The IEEE printf spec that Apple follows states:
A field width, or precision, or both, may be indicated by an asterisk
( '*' ). In this case an argument of type int supplies the field width
or precision.
This means that
label.text = [NSString stringWithFormat:#"%.*f",j,final]
might work, but I have no platform available to test it right now.
NSNumberFormatter has the ability to do what you want. Any of the following methods can be set using a variable before you format your string.
- (void)setMinimumIntegerDigits:(NSUInteger)number
- (void)setMinimumFractionDigits:(NSUInteger)number
- (void)setMaximumIntegerDigits:(NSUInteger)number
- (void)setMaximumFractionDigits:(NSUInteger)number
Data Formatting Guide - Number Formatters
I don't know if there's a one-liner that will do what you want, but you can always do:
NSString* formatString = [NSString stringWithFormat: #"%%.%if", j];
label.text = [NSString stringWithFormat:formatString, final];
You can use NSNumberFormatter,
NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[nf setFormatterBehavior:NSNumberFormatterBehaviorDefault];
[nf setNumberStyle:NSNumberFormatterDecimalStyle];
[nf setMaximumFractionDigits:j]; // Set the number of decimal places here
label.text = [nf stringFromNumber:[NSNumber numberWithFloat:final]];
[nf release];