CODEWITHSUNDEEP
iosroundingnsnumberformatterdecimal
ndpmcintosh
ndpmcintosh

Reputation: 88

NSNumberFormatter works with decimal separator but not with comma separator

I have been working on this for two days now. Time to consult stackoverflow.

I have an iOS user setting that allows selection of the decimal and grouping separators. It works perfectly when the separator is a decimal point, but when set to a decimal comma all the numerical entries are automatically rounded to the nearest whole number and any calculations lose precision.

The scheme is this:

//Use formatter to set decimal style for output
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
[formatter setMinimumFractionDigits:1];
[formatter setMaximumFractionDigits:5];

//Set number format from preferences
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSString *numberFormat = [userDefaults stringForKey:kNumberFormat];
if([numberFormat isEqualToString:@"Decimal Point"])
    {
    [formatter setDecimalSeparator:@"."];
    [formatter setGroupingSeparator:@","];
    }

    else
    {
    [formatter setDecimalSeparator:@","];
    [formatter setGroupingSeparator:@"."];
    }

NSNumber *number = [NSNumber numberWithDouble: result];
NSString* formattedResult = [formatter stringFromNumber:number];
[display_ setText: [NSString stringWithFormat:@"%@", formattedResult]];
[formatter release];

In decimal separator mode 5.5 + 5.5 = 11.0

But, in comma separator mode 5.5 is immediately truncated to 5.0 in the display and 5.5 + 5.5 = 10.

Not what I want!

Upvotes: 1

Views: 4265

Answers (1)

ndpmcintosh
ndpmcintosh

Reputation: 88

I was able to figured it out on my own. The number formatter was operating correctly. To get my analyzer class to work I had to send it a double that could not contain a comma decimal separator. But to get the display to look right in comma separator mode I had to send the string in the desired format to the display (e.g. 2.500,05), then reformat the string with a decimal points and commas as needed and then send that string to the analyzer as a double (e.g. 2,500.05). A little tricky since I am essentially swapping the decimal points and the commas. There is probably a slicker way to do it but this worked:

NSString *numberFormat = [userDefaults stringForKey:kNumberFormat];

//if the string has been entered using a decimal comma, do this
if([numberFormat isEqualToString:@"Decimal Comma"])
{

 NSString *displayString = [display_ text];
 NSString *newStringValue = [displayString 
           stringByReplacingOccurrencesOfString:@"," withString:@"x"];
 newStringValue = [newStringValue 
           stringByReplacingOccurrencesOfString:@"." withString:@","];
 newStringValue = [newStringValue 
           stringByReplacingOccurrencesOfString:@"x" withString:@"."];
 [display_ setText:displayString];
 [[self analyzer_] setFirstOperand:[newStringValue doubleValue]];
}

//there is no problem if the decimal separator is a decimal point, so 
//just send it as is
if([numberFormat isEqualToString:@"Decimal Point"])

{   
 [[self analyzer_] setOperand:[[display_ text] doubleValue]];   
}

Upvotes: 1

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