How to check if text field contains roman numerals

Question

Are there any methods available to check whether a UITextField contains roman numerals like i,ii,iii,iv...etc???

score 1 · Accepted Answer · answered Oct 23 '12 at 09:56

1

The only thing you can do (but maybe there are some other solution) is to check the UITextField string for those letter :

Bool find = NO;
NSArray *romans = [NSArray arrayWithObjects:@"i", @"ii", @"ii", @"vi", nil]; //Fill the array as you want

for(NSString *str in romans)
{
  if([textField.text rangeOfString:str].location != NSNotFound)
  {
    find = YES;
    break;
  }
}

if(find)
{
  //Roman letter found
}

answered Oct 23 '12 at 09:56

Ashbay

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Thanks. It works fine for a quick solution. But got to look for an approach thats gonna help in the long run – Ratikanta Patra Oct 23 '12 at 13:39

score 1 · Answer 2 · edited May 23 '17 at 12:12

1

You can use a regular expression through NSRegularExpression in any of the UITextFieldDelegate methods to check if your UITextField has a valid roman number. You can see an example of use of NSRegularExpression in: NSRegularExpression validate email

Your regex should be something like the one posted in: How do you match only valid roman numerals with a regular expression?

edited May 23 '17 at 12:12

Community

1
1

answered Oct 23 '12 at 10:03

atxe

5,029
2
36
50

score 1 · Answer 3 · answered Oct 23 '12 at 10:21

Use Regex + NSPredicate

-(BOOL)isValidForRoman:(NSString *)text
{
    NSString *romanRegex = @"^(?=.)(?i)M*(D?C{0,3}|C[DM])(L?X{0,3}|X[LC])(V?I{0,3}|I[VX])$";
    NSPredicate *romanTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", romanRegex]; 
    return ([romanTest evaluateWithObject:text]);
}

This Regex is for Roman validation.

How to check if text field contains roman numerals

3 Answers3