iOS 检测字符串中数字个数、特殊符号个数

-(int)numberOfDigits{
    int number = 0;
    for (int i = 0; i < self.length; i++) {
        unichar c = [self characterAtIndex:i];
        if((c > 47)&&(c < 58)) {
            number++;
        }
    }
    return number;
}

-(int)numberOfSpecialCharacter{
    NSString *specialCharacters = @"~`!@#$%^&*()_+-=[]|{};':\",.<>?/";//规定的特殊字符，可以自己随意添加
    int number = 0;
    for (int i = 0; i < self.length; i++) {
        NSString *subStr = [self substringWithRange:NSMakeRange(i, 1)];
        if([specialCharacters containsString:subStr]) {
            number++;
        }
    }
    return number;
}