Pour obtenir une clé
d'essai remplissez le formulaire ci-dessous
Demandez des tariffs
Nouvelle licence
Renouvellement de licence
--Sélectionnez la devise--
USD
EUR
RUB
* En cliquant sur ce bouton, vous acceptez notre politique de confidentialité

Free PVS-Studio license for Microsoft MVP specialists
To get the licence for your open-source project, please fill out this form
** En cliquant sur ce bouton, vous acceptez notre politique de confidentialité.

I am interested to try it on the platforms:
** En cliquant sur ce bouton, vous acceptez notre politique de confidentialité.

Votre message a été envoyé.

Nous vous répondrons à


Si vous n'avez toujours pas reçu de réponse, vérifiez votre dossier
Spam/Junk et cliquez sur le bouton "Not Spam".
De cette façon, vous ne manquerez la réponse de notre équipe.

>
>
>
V3179. Calling element access method fo…
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

V3179. Calling element access method for potentially empty collection may result in exception.

07 Sep 2022

The analyzer detected that a potentially empty collection has a method call that throws an exception if there are no elements in the collection.

To better understand this, let's look at the following example:

public static bool ComparisonWithFirst(List<string> list,
                                       string strForComparison)
{
  string itemForComparison = null;

  if (list != null && !list.Any())
  {
    itemForComparison = list.First();
  }
  ....
}

An attempt to access the first element from the collection results in 'InvalidOperationException'. Inside the then branch the collection is empty, because the 'list' has been checked for containing no elements.

Let's look at the fixed version:

public static bool ComparisonWithFirst(List<string> list,
                                       string strForComparison)
{
  string itemForComparison = null;

  if (list != null && list.Any())
  {
    itemForComparison = list.First();
  }
  ....
}

If we pass an empty collection to the method that doesn't expect this, we can get a similar error.

public static void ProcessList(List<string> list)
{
  if (list.Any())
    return;

  CompareFirstWithAll(list);
}

public static void CompareFirstWithAll(List<string> list)
{
  string itemForComparison = list.First();
  ....
}

The 'ProcessList' method contains a typo, so the empty 'list' collection is passed to the 'CompareFirstWithAll' method. The 'CompareFirstWithAll' method does not expect to receive an empty collection.

Let's look at the fixed version:

public static void ProcessList(List<string> list)
{
  if (!list.Any())
    return;

  CompareFirstWithAll(list);
}
Unicorn with delicious cookie
Nous utilisons des cookies pour améliorer votre expérience de navigation. En savoir plus
Accepter