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@bennythemink
Created July 17, 2014 06:02
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Small but handy NSString extension for checking if the string is a valid email address or is a valid number
@interface NSString (Extension)
- (BOOL) isAnEmail;
- (BOOL) isNumeric;
@end
@implementation NSString (Extension)
/**
* Determines if the current string is a valid email address.
*
* @return BOOL - True if the string is a valid email address.
*/
- (BOOL) isAnEmail
{
NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
return [emailTest evaluateWithObject:self];
}
/**
* Determines if the current NSString is numeric or not. It also accounts for the localised (Germany for example use "," instead of ".") decimal point and includes these as a valid number.
*
* @return BOOL - True if the string is numeric.
*/
- (BOOL) isNumeric
{
NSString *localDecimalSymbol = [[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator];
NSMutableCharacterSet *decimalCharacterSet = [NSMutableCharacterSet characterSetWithCharactersInString:localDecimalSymbol];
[decimalCharacterSet formUnionWithCharacterSet:[NSCharacterSet alphanumericCharacterSet]];
NSCharacterSet* nonNumbers = [decimalCharacterSet invertedSet];
NSRange r = [self rangeOfCharacterFromSet: nonNumbers];
if (r.location == NSNotFound)
{
// check to see how many times the decimal symbol appears in the string. It should only appear once for the number to be numeric.
int numberOfOccurances = [[self componentsSeparatedByString:localDecimalSymbol] count]-1;
return (numberOfOccurances > 1) ? NO : YES;
}
else return NO;
}
@end
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