to the top
close form

Fill out the form in 2 simple steps below:

Your contact information:

Step 1

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.

>
>
>
V551. Unreachable code under a 'case' l…
menu mobile close menu
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
toggle menu Contents

V551. Unreachable code under a 'case' label.

Jun 30 2011

The analyzer detected a potential error: one of the switch() operator's branches never gets control. The reason is that the switch() operator's argument cannot accept the value defined in the case operator.

Consider this sample:

char ch = strText[i];
switch (ch)
{
case '<':
  strHTML += "<";
  bLastCharSpace = FALSE;
  nNonbreakChars++;
  break;
case '>':
  strHTML += ">";
  bLastCharSpace = FALSE;
  nNonbreakChars++;
  break;
case 0xB7:
case 0xBB:
  strHTML += ch;
  strHTML += "<wbr>";
  bLastCharSpace = FALSE;
  nNonbreakChars = 0;
  break;
...
}

The branch following "case 0xB7:" and "case 0xBB:" in this code will never get control. The 'ch' variable has the 'char' type and therefore the range of its values is [-128..127]. The comparisons "ch == 0xB7" and "ch==0xBB" will always be false. To make the code correct, we must cast the 'ch' variable to the 'unsigned char' type:

unsigned char ch = strText[i];
switch (ch)
{
...
case 0xB7:
case 0xBB:
  strHTML += ch;
  strHTML += "<wbr>";
  bLastCharSpace = FALSE;
  nNonbreakChars = 0;
  break;
...
}

This diagnostic is classified as:

You can look at examples of errors detected by the V551 diagnostic.

Unicorn with delicious cookie
Our website uses cookies to enhance your browsing experience.
Accept