My objective is to create a customer calculator application for iPhone and I am using Xcode to write my application. My problem, that I cannot find a solution for, is how to format a number that uses decimals (with extra zeros) without switching into scientific notation
I tried...
buttonScreen.text = [NSString stringWithFormat:@"%0.f",currentNumber];
%0.f formatting always rounds so if the user types in "4.23" it displays "4"
%f formats numbers with 6 decimals (typing in '5' displays as '5.000000'), but I don't want to show extra zeros on the end of the number.
%10.4f is something else that I have seen in my reading to find the solution, but my problem is that I don't know how many decimals will be in the answer, and I may want zero decimals or 10 decimals depending on the number.
The following are examples of numbers I'd like to display (without the commas): A whole number larger than 6 digits, a decimal number with more than 6 digits.
123,456,789;
0.123456789;
12345.6789;
-123,456,789;
-0.23456789;
-12345.6789;
*This is a spiritual repost to my earlier question "How to Format Numbers without scientific notation or decimals" which I poorly phrased as I intended to write 'unnecessary (extra zeros),' but upon rereading my post clearly witnessed my inability to convey that at any point in my question.
Use the NSNumberFormatter class.
First define the formatter:
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
Then you can define various properties of the formatter:
formatter.numberStyle = NSNumberFormatterDecimalStyle;
formatter.maximumIntigerDigits = 3;
formatter.minimumFractionDigits = 3;
formatter.maximumFractionDigits = 8;
formatter.usesSignificantDigits = NO;
formatter.usesGroupingSeparator = YES;
formatter.groupingSeparator = @",";
formatter.decimalSeparator = @".";
....
You format the number into a string like this:
NSString *formattedNumber = [formatter stringFromNumber:num];
Play around with it. Its pretty simple, but may take some work to get the look you would like.