NSNumberFormatter *numberFormatter = [[[NSNumberFormatter alloc] init] autorelease];
[numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
[numberFormatter setMaximumFractionDigits:2];
[numberFormatter setDecimalSeparator:@"."];
[numberFormatter setGroupingSeparator:@""];
NSString *example1 = [numberFormatter stringFromNumber:[NSNumber numberWithFloat:123456.1234]];
NSLog(@"%@", example1);
NSString *example2 = [numberFormatter stringFromNumber:[NSNumber numberWithFloat:123456.00]];
NSLog(@"%@", example2);

NSLog(@"%g", 1.000000);    => 1
NSLog(@"%g", 1.123456789);  => 1.12346
NSLog(@"%.1g", 1.123456789);  => 1
NSLog(@"%.2g", 1.123456789);  => 1.1
NSLog(@"%.3g", 1.123456789);  => 1.12
NSLog(@"%.4g", 1.123456789);  => 1.123

let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .decimal
numberFormatter.maximumFractionDigits = 2
numberFormatter.decimalSeparator = "."
numberFormatter.groupingSeparator = ""
let example1 = numberFormatter.string(from: 123456.1234)!
print(example1)
let example2 = numberFormatter.string(from: 123456.00)!
print(example2)