Checking if NSString is Integer [duplicate]

Answer 1

-(BOOL)isANumber:(NSString *)string{
    NSPredicate *numberPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES '^[0-9]+$'"];
    return [numberPredicate evaluateWithObject:string];
}

Answer 2

I have used [NSCharacterSet decimalDigitCharacterSet]. Definitely works well.

NSCharacterSet* notDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];

if ([newString rangeOfCharacterFromSet:notDigits].location == NSNotFound)
{
// newString consists only of the digits 0 through 9
}