CODEWITHSUNDEEP
iosobjective-cnsstringformat-specifiersstringwithformat
user2933653
user2933653

Reputation: 89

How to not show unnecessary zeros when given integers but still have float answers when needed

I have an app I'm developing and one of my features is giving answers in float or double values when needed and an integer when the answer is a whole number

so for example if the answer comes out to 8.52 the answer becomes 8.52 but when the answer is 8 the answer is 8 instead of 8.0000, i don't want it to show all the extra 0s. 

- (IBAction) equalsbutton {
NSString *val = display.text;
switch(operation) {

    case Plus :
        display.text= [NSString stringWithFormat:@"%qi",[val longLongValue]+[storage longLongValue]];

    case Plus2 :
        display.text= [NSString stringWithFormat:@"%f",[val doubleValue]+[storage doubleValue]];

this code doesn't seem to work

Upvotes: 7

Views: 3509

Answers (4)

Alan Scarpa
Alan Scarpa

Reputation: 3560

Easiest way, is NSNumberFormatter. It will only display the decimal if needed. Example (Swift):

let num1: Double = 5
let num2: Double = 5.52
let numberFormatter = NSNumberFormatter()
numberFormatter.numberStyle = .DecimalStyle
print(numberFormatter.stringFromNumber(NSNumber(double: num1)))
print(numberFormatter.stringFromNumber(NSNumber(double: num2)))

This will print 5 and then 5.52.

Upvotes: 0

Brian Shamblen
Brian Shamblen

Reputation: 4703

You can try this method call:

[NSString stringWithFormat:@"%.0f", [val doubleValue] + [storage doubleValue]];

Upvotes: 0

Nathan
Nathan

Reputation: 1647

EDIT Formatting

Here is a way that I did this when I needed to display currency (but whole numbers if the currency was a round number.

First we get the money amount as a string 

NSString *earnString = _money.payout.displayableAmount;

NSMutableString *strippedString = [NSMutableString
                                   stringWithCapacity:earnString.length];

//scan the string to remove anything but the numbers (including decimals points)

NSScanner *scanner = [NSScanner scannerWithString:earnString];
NSCharacterSet *numbers = [NSCharacterSet
                           characterSetWithCharactersInString:@"0123456789"];

while ([scanner isAtEnd] == NO) {
    NSString *buffer;
    if ([scanner scanCharactersFromSet:numbers intoString:&buffer]) {
        [strippedString appendString:buffer];

    } else {
        [scanner setScanLocation:([scanner scanLocation] + 1)];
    }
}
//create an int with this new string
int earnInt = [strippedString intValue];

//if the string is less than 100 then we only had "change" so display that amount if(earnInt < 100){ //Dollar amount is less then dollar display just the cents and the cent symbol NSString *centString = [NSString stringWithFormat:@"%i¢", earnInt]; earnAmount.text = centString;

//if we have a number evenly divisible by 100 then we have whole dollar amount, display that properly }else if(earnInt % 100 == 0){

    //The amount is exactly a dollar, display the whole number
    NSString *wholeDollar = [NSString stringWithFormat:@"$%i", (earnInt/100)];
    earnAmount.text = wholeDollar;

//finally if we have a mixed number then put them back together with the decimal in-between.

}else{
    //Dollar amount is not exactly a dollar display the entire amount
    NSString *dollarString = [NSString stringWithFormat: @"$%0d.%02d", (earnInt / 100), (earnInt % 100)];
    earnAmount.text = dollarString;

}

Hopefully this helps you out...

Upvotes: 0

Joel Fischer
Joel Fischer

Reputation: 6597

These specifiers are standard IEEE format specifiers, which means that you can do things like %.2f to only show 2 decimal places on a float variable.

You could also convert it into an int, and then use the %d format specifier if you wanted to do it that way.

Here's also Apple's documentation on the subject.

EDIT: Based on your comment on the other post, it looks like you're looking for %g, which will essentially remove the extraneous 0's from floats.

display.text= [NSString stringWithFormat:@"%g",[val doubleValue]+[storage doubleValue]];

I found the answer here: Use printf to format floats without decimal places if only trailing 0s

Upvotes: 13

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