統計字符串中某個字符的個數

int numberPoint = 0;

    

    for (int i = 0; i<self.myTextCostWeight.text.length; i++)

    {

        NSString * temp = [self.myTextCostWeight.text substringWithRange:NSMakeRange(i, 1)];

        if ([temp isEqualToString:@"."])

        {

            numberPoint ++;

        }

    

    }

    

    if (numberPoint >=2)

    {

        UIAlertView * alert = [[UIAlertView alloc]initWithTitle:@"價格" message:@"輸入太多 . " delegate:self cancelButtonTitle:nil otherButtonTitles:@"確認", nil];

        [alert show];

    }