how to validate UITextfield such that it should contain only numbers,no os characters less than 2

Question

I want to validate my UITextfield for number of characters less than 2 and only numbers should be entered... seen this

What do you mean with only characters less than 2? – mfaerevaag Jun 07 '13 at 09:58 — mfaerevaag, Jun 07 '13 at 09:58
try the answer posted... – Agent Chocks. Jun 07 '13 at 10:04 — Agent Chocks., Jun 07 '13 at 10:04

score 6 · Answer 1 · answered Jun 07 '13 at 10:02

Try this one...

#define NUMBERS_ONLY @"1234567890"
#define CHARACTER_LIMIT 2

and in this method----

 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string  {
        NSUInteger newLength = [textField.text length] + [string length] - range.length;
        NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:NUMBERS_ONLY] invertedSet];
        NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
        return (([string isEqualToString:filtered])&&(newLength <= CHARACTER_LIMIT));
    }

score 1 · Answer 2 · answered Sep 25 '13 at 15:14

This works!!

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{
if ([string isEqualToString:@""]) return YES;
unichar c = [string characterAtIndex:0];
    if ([[NSCharacterSet decimalDigitCharacterSet] characterIsMember:c])
    {
        int maxVal = 2;
        if (textField.text.length >= maxVal)
            return NO;
        else
            return YES;
    } else {
        return NO;
    }
}

score 0 · Answer 3 · answered Jun 07 '13 at 09:58

0

The standard way of dealing with this in iOS is attaching a UITextFieldDelegate to your UITextField, and implement textField:shouldChangeCharactersInRange:replacementString: method. Inside this method you can validate the string

use property length to achieve this

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    if([textField.text length]<2)
        return YES;
    else
        return NO;
}

answered Jun 07 '13 at 09:58

Lithu T.V

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Actually the standard in iOS and MacOS X is to use key-value coding validation (https://developer.apple.com/library/ios/documentation/cocoa/conceptual/KeyValueCoding/Articles/Validation.html). An example of this is: https://github.com/quellish/KVCValidationExample – quellish Jul 24 '14 at 20:26

score 0 · Answer 4 · answered Jun 07 '13 at 10:02

try like this,

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    if([textField.text length]<2)
        return YES;
    else
        return NO;
}

and assign NSNumberkeyboard type to the textfield.

score 0 · Answer 5 · answered Jun 07 '13 at 10:03

Another way to declare a NSCharaterSet with all letters and check that the field's text does not contain any of them:

NSCharacterSet *alphabet = [NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyz"]
if ([[self.label.text lowercaseString] rangeOfCharacterFromSet:alphabet].location != NSNotFound) 
{
     NSLog(@"Found letters!");
}

how to validate UITextfield such that it should contain only numbers,no os characters less than 2

5 Answers5