To get a trial key
fill out the form below
Team license
Enterprise license
** By clicking this button you agree to our Privacy Policy statement

Request our prices
New License
License Renewal
--Select currency--
USD
EUR
RUB
* By clicking this button you agree to our Privacy Policy statement

Free PVS-Studio license for Microsoft MVP specialists
** By clicking this button you agree to our Privacy Policy statement

To get the licence for your open-source project, please fill out this form
** By clicking this button you agree to our Privacy Policy statement

I am interested to try it on the platforms:
** By clicking this button you agree to our Privacy Policy statement

Message submitted.

Your message has been sent. We will email you at


If you haven't received our response, please do the following:
check your Spam/Junk folder and click the "Not Spam" button for our message.
This way, you won't miss messages from our team in the future.

>
>
>
V3181. The result of '&' operator is '0…
Analyzer diagnostics
General Analysis (C++)
General Analysis (C#)
General Analysis (Java)
Diagnosis of micro-optimizations (C++)
Diagnosis of 64-bit errors (Viva64, C++)
Customer specific requests (C++)
MISRA errors
AUTOSAR errors
OWASP errors (C#)
Problems related to code analyzer
Additional information
Contents

V3181. The result of '&' operator is '0' because one of the operands is '0'.

Sep 07 2022

The analyzer has detected that there is a bitwise 'AND' (&) operation with an operand equal to 0. A code fragment may contain incorrect operator or operand.

Example:

public enum TypeAttr
{
  NotPublic = 0x0,
  Public = 0x1,
  NestedPublic = 0x2,
  NestedPrivate = 0x3
}

public static bool IsNotPublic(TypeAttr type)
{
  return (type & TypeAttr.NotPublic) == TypeAttr.NotPublic;
}

The 'IsNotPublic' method checks if the argument of the 'TypeAttr' type has the 'NotPublic' flag.

Such a method of checking doesn't have any practical sense since the 'TypeAttr.NotPublic' flag has a zero value, which means using this flag as an operand of the '&' operator always results in a zero value. Thus, in the presented implementation, we always get the true condition.

The correct implementation of the check may look as follows:

public static bool IsNotPublic(TypeAttr type)
{
  return type == TypeAttr.NotPublic;
}

The analyzer will also issue a warning for the use of the operand that is '0' with the '&=' operator. This code also looks questionable, because if one of the operands is '0', the result of the expression is also '0'.

Unicorn with delicious cookie
Our website uses cookies to enhance your browsing experience. Would you like to learn more?
Accept