How do you dynamically format a number to have commas in a UITextField entry?

Question

I want to have commas dynamically added to my numeric UITextField entry while the user is typing.

For example: 123,456 and 12,345,678

Answer 1

Windy please keep in mind the commas should get add to the number itself, not like user has to enter them.

First

// Add a "textFieldDidChange" notification method to the text field control.
[textField addTarget:self 
          action:@selector(textFieldDidChange:) 
forControlEvents:UIControlEventEditingChanged];

You have to change to change the Text yourself. And the Code that will add the commas is

-(void) textFieldDidChange {

    NSNumberFormatter *formatter = [NSNumberFormatter new];
    [formatter setNumberStyle:NSNumberFormatterDecimalStyle]; // this line is important!

    NSString *formatted = [formatter stringFromNumber:[NSNumber numberWithInteger:2000000]];
    NSLog(@"the Formatted String is  %@",formatted);

   textField.text = formatted;
}