# V2538. MISRA. The value of uninitialized variable should not be used.

This diagnostic rule is based on the software development guidelines developed by MISRA (Motor Industry Software Reliability Association).

If a variable of a POD type isn't initialized explicitly and doesn't have an initializer by default, its value will be undefined. Usage of such value will lead to undefined behavior.

Simple synthetic example:

    int Aa = Get();
    int Ab;
    if (Ab) // Ab - uninitialized variable
      Ab = Foo();
    else
      Ab = 0;

Usually errors of using uninitialized variables occur through misprints. For example, it may appear that a different variable should be used in this place. Correct code variant:

    int Aa = Get();
    int Ab;
    if (Aa) // OK
      Ab = Foo();
    else
      Ab = 0;

This diagnostic is classified as:

MISRA-C-2012-9.1 MISRA-C-2023-9.1 MISRA-CPP-2008-8.5.1