Our website uses cookies to enhance your browsing experience.
Accept
to the top
close form

Fill out the form in 2 simple steps below:

Your contact information:

Step 1
Congratulations! This is your promo code!

Desired license type:

Step 2
Team license
Enterprise license
** By clicking this button you agree to our Privacy Policy statement
close form
Request our prices
New License
License Renewal
--Select currency--
USD
EUR
* By clicking this button you agree to our Privacy Policy statement

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

close form
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

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

close form
check circle
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.

>
>
>
V3170. Both operands of the '??' operat…
menu mobile close menu
Analyzer diagnostics
General Analysis (C++)
General Analysis (C#)
General Analysis (Java)
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
toggle menu Contents

V3170. Both operands of the '??' operator are identical.

Dec 03 2020

The analyzer has found that both operands used in either the '??'' or '??=' operator are the same. Most likely, this operation is erroneous. Such errors may occur as a result of a typo or inattentive copy-paste.

Consider an example of a similar error that appears when using the '??' operator:

string SomeMethod()
{
  String expr1 = Foo();
  String expr2 = Bar();
  ....

  return expr1 ?? expr1;
}

'SomeMethod' will always return the same value whether the 'expr1' variable is 'null' or not. Therefore, the 'expr1 ?? expr1' expression in 'SomeMethod' does not make sense. Most likely, there was a typo, and the correct version of the expression should look like this:

return expr1 ?? expr2;

A similar error can be made when using the '??=' operator:

void SomeMethod()
{
  String expr1 = Foo();
  String expr2 = Bar();
  ....

  expr1 ??= expr1;
  ....

  DoSmt(expr1);
}

In this case, an error similar to the one described in the previous example was made. Fixed code:

expr1 ??= expr2;

This diagnostic is classified as: