How to use NSNumberFormatter to insert blank space to NSString?

Question

I want to write a UITextField that can auto format a number to bank number.

For example: Input 1234567890098765 will be automatically displayed as 1234 5678 9009 8765.

I'll use textFieldDelegate to do it, but I don't know how to use NSNumberFormatter.

How can I do it?

Answer 1

Using NSNumberFormatter is simple.

NSNumber *number = [NSNumber numberWithLongLong:1234567890098765];
NSNumberFormatter *formatter = [NSNumberFormatter new];
[formatter setUsesGroupingSeparator:YES];
[formatter setGroupingSize:3];
// [formatter setGroupingSeparator:@"\u00a0"];
NSString *string = [formatter stringFromNumber:number];

I deliberately commented the line that sets the formatter's grouping separator as it may be better to use the default one, which is provided by the user's locale (e.g. , in the USA, . in Germany and ' in Switzerland). Also please note that iOS doesn't use a space as a separator but a non-breaking space (U+00A0).