Question

I have been trying to use NSScanner or even a for loop in a string to remove duplicate NSDecimalSeparator. How to do that?

Note: NSDecimalSeparator is not “just a comma”. It changes according to the iOS current localization. So, any implementation applying a search for duplicate “comma” won’t work.

Answer 1

NSDecimalSeparator is deprecated. I would recommend using NSNumberFormatter:

//getting default formatter
NSNumberFormatter* numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setFormatterBehavior: [NSNumberFormatter defaultFormatterBehavior]];

//creating two strings, one with single and one with double separator
NSString *separator = [numberFormatter decimalSeparator];
NSString *doubleSeparator = [NSString stringWithFormat:@"%@%@", separator, separator];

NSLog(@"decimal separator: %@", separator);

//creating example string
NSString *str = [NSString stringWithFormat:@"single: %@ double: %@", separator, doubleSeparator];

NSLog(@"example string: %@", str);

//replacing double separator with single separator
NSString *modified = [str stringByReplacingOccurrencesOfString: doubleSeparator withString:separator];

NSLog(@"modified string: %@", modified);

Edit:
Regarding your comment about “23,45,67” string, here it is:

NSString *str2 = @"23,45,67";

NSMutableArray *temp = [NSMutableArray arrayWithArray: [str2 componentsSeparatedByString:separator]];

NSString *last = [temp lastObject];

[temp removeLastObject];

NSString *newStr = [NSString stringWithFormat:@"%@%@%@", [temp componentsJoinedByString:@""], separator, last];

NSLog(@"result: %@", newStr);

Edit 2:
Code to keep only first separator is similar:

NSMutableArray *temp2 = [NSMutableArray arrayWithArray: [str2 componentsSeparatedByString:separator]];

NSString *first = [temp2 objectAtIndex:0];

[temp2 removeObject:first];

NSString *newStr2 = [NSString stringWithFormat:@"%@%@%@", first, separator, [temp2 componentsJoinedByString:@""]];

NSLog(@"result2: %@", newStr2);