spot7.org logo
Home PHP C# C++ Android Java Javascript Python IOS SQL HTML Categories

Unable to return NULL in a function that expects an integer return type


If the return type is int, you can't return a NULL. To show an error, you could instead return a special value like zero or -1, if you check for that value in any calling function. Lots of functions return nonnegative numbers on success, or -1 on error.

NULL cannot be stored in an int variable, unlike in SQL, for example. If you ignore the warning and return NULL anyway, then NULL will be casted to zero. The calling function won't be able to tell whether you returned NULL or zero.

If your function only needs to indicate success or failure, then it's common to return 1 for success, and zero for failure. Zero means "false" when treated as a boolean value (like in if statements), and non-zero means "true."


Categories : C

Related to : Unable to return NULL in a function that expects an integer return type
What does return; in a C function of boolean return type return?
This is undefined behavior, a return statement without an expression shall only be used in a function whose return type is void. This is covered in the draft C99 standard section 6.8.6.4 The return statement: [...]A return statement without an expression shall only appear in a function whose return type is void. Interestingly this is an error by default when using clang but gcc without any

Categories : C
Compare values of return type Boolean and Integer
There's a shorter way to write it: Instead of: if (BServer.y.equals(new Integer(1))) { return true; } else { return false; } write : return (BServer.y == 1) ? true : false;

Categories : Java
Unable to return List object
You are not adding the results from recursive calls. So ideally you are getting the results from only the last directory which may not have some files.. Try this: foreach (DirectoryInfo SubdirInfo in DirInfo.GetDirectories()) { FileInfoList.AddRange(SearchFileSystem(SubdirInfo, FileList)); }

Categories : C#
Unable to return string forms of DateField and TimeField field values
As mentioned in the comment, looks like the console session still remembered the previous code even though the actual code has been changed. I just had to restart the shell again to see the changes.

Categories : Python
Return value for parent function (nested); Waiting for asynchronous function
You might find it more useful to write a constructor that returns a "promisified Image", ie an instance of window.Image with a custom .setSrc() method that returns a promise. Something like this (untested) should do it : function PromisifiedImg() { var img = new Image(); img.setSrc = function(src, limits) { var dfrd = $.Deferred(); img.onload = function() { i

Categories : Jquery
Recently Add
Rewrite of IDA decompiled function
Computing the average of grades in C
passing structures to functions
Use semaphores for handling sockets in C
How to search for a string pattern inside html, coding in C?
sprintf invalid format '%d'
Why can't this c program run correctly?
Low Pass filter in C
Child process does not print anything
C: datatypes. sqrt function working with int why?
How to implement Serial Port Profile Link Command used in ConnectBlue Bluetooth Module?
Rerunning cancelled pthread
How to print out a string that is pointed to by a char pointer?
Can unverified scanf call cause an undefined behavior?
nested structures in C
Portable Makevars for R package using C, GSL and OpenMP with help of Rcpp
program doesn't run(getting RUN FINISHED Segmentation fault core dumped)
Finding the sign of a Lua number, from C
Width of symbols created by gcc's objectcopy
Strange behavior when using free in c program
Can't open image C
Strange C code - dynamic arrays?
C program printing weird characters
Fault in decimal to binary in c
How to detect broken pipe on input?
How can I ivestigate use of the register keyword in C?
File scaning with fscanf
why gcc generates "leal -8240(%ebp), %eax; cmpl $1, %eax; ja XXX" instead of jmp instruction?
Wierd Problems With My Own Custom Written Word Search Algorithm
Trouble with making a shell in C
© Copyright 2017 spot7.org Publishing Limited. All rights reserved.