How can I limit the number of decimal points in a UITextField?
Implement the shouldChangeCharactersInRange method like this:
// Only allow one decimal point
// Example assumes ARC - Implement proper memory management if not using.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSString *newString = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSArray *arrayOfString = [newString componentsSeparatedByString:@"."];
if ([arrayOfString count] > 2 )
return NO;
return YES;
}
This creates an array of strings split by the decimal point, so if there is more than one decimal point we will have at least 3 elements in the array.
Here is an example with a regular expression, the example limits to only one decimal point and 2 decimals. You can tweak it to fit your needs.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSString *newString = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSString *expression = @"^[0-9]*((\\.|,)[0-9]{0,2})?$";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:expression options:NSRegularExpressionCaseInsensitive error:&error];
NSUInteger numberOfMatches = [regex numberOfMatchesInString:newString options:0 range:NSMakeRange(0, [newString length])];
return numberOfMatches != 0;
}