formatting - iOS convert large numbers to smaller format -

how can convert numbers more 3 digits down 4 digit or less number?

this mean:

10345 = 10.3k 10012 = 10k 123546 = 123.5k 4384324 = 4.3m 

rounding not entirely important, added plus.

i have looked nsnumberformatter have not found proper solution, , have yet find proper solution here on so. appreciated, thanks!

-(nsstring*) suffixnumber:(nsnumber*)number {     if (!number)         return @"";      long long num = [number longlongvalue];      int s = ( (num < 0) ? -1 : (num > 0) ? 1 : 0 );     nsstring* sign = (s == -1 ? @"-" : @"" );      num = llabs(num);      if (num < 1000)         return [nsstring stringwithformat:@"%@%lld",sign,num];      int exp = (int) (log10l(num) / 3.f); //log10l(1000));      nsarray* units = @[@"k",@"m",@"g",@"t",@"p",@"e"];      return [nsstring stringwithformat:@"%@%.1f%@",sign, (num / pow(1000, exp)), [units objectatindex:(exp-1)]]; } 

sample usage

nslog(@"%@",[self suffixnumber:@100]); // 100 nslog(@"%@",[self suffixnumber:@1000]); // 1.0k nslog(@"%@",[self suffixnumber:@1500]); // 1.5k nslog(@"%@",[self suffixnumber:@24000]); // 24.0k nslog(@"%@",[self suffixnumber:@99900]); // 99.9k nslog(@"%@",[self suffixnumber:@99999]); // 100.0k nslog(@"%@",[self suffixnumber:@109999]); // 110.0k nslog(@"%@",[self suffixnumber:@5109999]); // 5.1m nslog(@"%@",[self suffixnumber:@8465445223]); // 8.5g nslog(@"%@",[self suffixnumber:[nsnumber numberwithint:-120]]); // -120 nslog(@"%@",[self suffixnumber:[nsnumber numberwithlong:-5000000]]); // -5.0m nslog(@"%@",[self suffixnumber:[nsnumber numberwithdouble:-3.5f]]); // -3 nslog(@"%@",[self suffixnumber:[nsnumber numberwithdouble:-4000.63f]]); // -4.0k 

[update]

swift version below:

func suffixnumber(number:nsnumber) -> nsstring {      var num:double = number.doublevalue;     let sign = ((num < 0) ? "-" : "" );      num = fabs(num);      if (num < 1000.0){         return "\(sign)\(num)";     }      let exp:int = int(log10(num) / 3.0 ); //log10(1000));      let units:[string] = ["k","m","g","t","p","e"];      let roundednum:double = round(10 * num / pow(1000.0,double(exp))) / 10;      return "\(sign)\(roundednum)\(units[exp-1])"; } 

sample usage

print(self.suffixnumber(nsnumber(long: 100))); // 100.0 print(self.suffixnumber(nsnumber(long: 1000))); // 1.0k print(self.suffixnumber(nsnumber(long: 1500))); // 1.5k print(self.suffixnumber(nsnumber(long: 24000))); // 24.0k print(self.suffixnumber(nsnumber(longlong: 99900))); // 99.9k print(self.suffixnumber(nsnumber(longlong: 99999))); // 100.0k print(self.suffixnumber(nsnumber(longlong: 109999))); // 110.0k print(self.suffixnumber(nsnumber(longlong: 5109999))); // 5.1k print(self.suffixnumber(nsnumber(longlong: 8465445223))); // 8.5g print(self.suffixnumber(nsnumber(long: -120))); // -120.0 print(self.suffixnumber(nsnumber(longlong: -5000000))); // -5.0m print(self.suffixnumber(nsnumber(float: -3.5))); // -3.5 print(self.suffixnumber(nsnumber(float: -4000.63))); // -4.0k 

hope helps