Rounding float number upto two decimal places

Question

I am trying to round a floating value upto two decimal places. I am using objective-c

e.g 1.47567 should be like this , 1.47 .. Please help

Thnx .

That's not "rounding", it's truncation. Since the third digit is `5`, rounding would be `1.48`. Which one would you like to do? — Sergey Kalinichenko, Nov 21 '12 at 10:51
see http://stackoverflow.com/questions/560517/make-a-float-only-show-two-decimal-places — Cfr, Nov 21 '12 at 10:56
http://stackoverflow.com/questions/752817/rounding-numbers-in-objective-c duplicate? — hd1, Nov 21 '12 at 13:05

score 2 · Accepted Answer · answered Nov 21 '12 at 11:00

2

    float num = 1.47567;
    num *= 100;
    if(num >= 0) num += 0.5; else num -= 0.5;
    long round = num;
    num = round;
    num /= 100;
    NSLog(@"%.2f",num);

answered Nov 21 '12 at 11:00

Nookaraju

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I don't have to re-format it , I want that if after rounding i write NSLog(@"%f",num); then i should get 1.47 . . – Waqas Nov 21 '12 at 11:13

score 1 · Answer 2 · answered Mar 26 '13 at 12:40

1

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];  
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];  
[formatter setMaximumFractionDigits:2];

NSString *formattedNumber = [formatter stringFromNumber:@(self.speed)];

answered Mar 26 '13 at 12:40

Burhanuddin Sunelwala

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I would always use NSNumberFormatter, since it's easier this way to re-use formats. Use NSNumberFormatterRoundDown to avoid rounding. Also helpful: http://stackoverflow.com/questions/15264109/how-to-avoid-rounding-off-in-nsnumberformatter – lukas_o May 19 '15 at 14:56

score 0 · Answer 3 · answered Nov 21 '12 at 11:13

0

double value = 1.47567;
double roundedValue = round(value * 100.0) / 100.0;

Of course you can use a named constant in place of 100.0. This is just a demo.

answered Nov 21 '12 at 11:13

Davyd Geyl

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By applying NSLog(@"Rounded value is :%f",roundedValue); It prints 1.480000 .. but i want that rounded value should have 1.47 or lets say 1.48 . – Waqas Nov 21 '12 at 11:27
In the comment @jimpic's answer you said you did not want to print it, but to use it. So, when you use it, what do you think is the difference between 1.48 and 1.480000? – Davyd Geyl Nov 21 '12 at 23:09

score 0 · Answer 4 · answered Nov 10 '13 at 19:00

Do this

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];  
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];  
[formatter setMaximumFractionDigits:2];

NSString *formattedNumber = [formatter stringFromNumber:@(self.speed)];

float numTwoDecimalDigits = atof([formattedNumber UTF8String]);

score -1 · Answer 5 · answered Nov 21 '12 at 10:56

-1

NSLog(@"%.2f", 1.47567);

would round to two decimal places. If you want to "cut", there are different options. For example:

NSLog(@"%.2f", floor(1.47567 * 100) / 100);

answered Nov 21 '12 at 10:56

jimpic

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I am not about to print the value. But i have to use it . All I want that after being round , my variable should contain like 1.45. . – Waqas Nov 21 '12 at 11:00

Rounding float number upto two decimal places

5 Answers5