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    <p>Just initializing all the variables may not be a good idea.</p> <p>Reliable behavior generally depends on variables having values known to be correct ("guaranteed by construction" to be correct). The problem with uninitialized variables isn't simply that they have unknown values. Obviously being unknown is a problem, but again the desired sate is having known <em>and correct</em> values. Initializing a variable to a known value that is not correct does not yield reliable behavior.</p> <p>Not infrequently it happens that there is no 'default' value that is correct to use as a fallback if more complicated initialization fails. A program may choose not to initialize a variable with a value if that value must be over-written before the variable can be used.</p> <p>Initializing a variable to a default value may have a few problems in such cases. Often 'default' values are inoffensive in that if they are used the consequences aren't immediately obvious. That's not generally desirable because as the developer you want to notice when things go wrong. You can avoid this problem by picking default values that will have obvious consequences, but that doesn't solve a second issue; Static analyzers can often detect and report when an uninitialized variable is used. If there's a problem with some complicated initialization logic such that no value is set, you want that to be detectable. Setting a default value prevents static analysis from detecting such cases. So there are cases where you do not want to initialize variables.</p> <hr> <p>With pointers the default value is typically <code>nullptr</code>, which to a certain extent avoids the first issue discussed above because dereferencing a null pointer typically produces an immediate crash (good for debugging). However code might also detect a null pointer and report an error (good for debugging) or might fall back to some other method (bad for debugging). You may be better off using static analysis to detect usages of uninitialized pointers rather than initializing them. Though static analysis may detect dereferencing of null pointers it won't detect when null pointers cause error reporting or fallback routines to be used.</p> <hr> <p>In response to your comment:</p> <blockquote> <p>The major problems that i see are</p> <ul> <li>Pointers to local variables are returned from functions.</li> <li>Almost all the pointer variables are not initialized. I am sure that AIX does provide this comfort for the customer in the earlier platform however i really doubt that the code would run flawlessly in Linux when it is being put to real test (Production).</li> <li>I cannot deliver partial solutions which may work. i prefer to give the best to my customer who pays me for my work. So Wont prefer to use workarounds.</li> <li>Quality cannot be compromised.</li> </ul> </blockquote> <ul> <li>fix them (and pay special attention to correctly cleaning up)</li> <li>As I argue above simply lacking an initializer is not in and of itself a defect. There is only a defect if the uninitialized value is actually used in an illegal manner. I'm not sure what you mean about AIX providing comfort.</li> <li>As I argue above the 'partial solution' and 'workaround' would be to blindly initialize everything.</li> <li>Again, blindly initializing everything can result not only in useless work, but it can actually compromise quality by taking away some tools for detecting bugs.</li> </ul>
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    1. COThe major problems that i see are -Pointers to local variables are returned from functions. -Almost all the pointer variables are not initialized. I am sure that AIX does provide this comfort for the customer in the earlier platform however i really doubt that the code would run flawlessly in Linux when it is being put to real test (Production). -I cannot deliver partial solutions which may work. i prefer to give the best to my customer who pays me for my work. So Wont prefer to use workarounds. -Quality cannot be compromised.
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