In C, I did not notice any effect of the extern keyword used before function declaration. At first, I thought that when defining extern int f(); in a single file forces you to implement it outside of the file’s scope. However I found out that both: extern int f(); int f() {return 0;} and extern … Read more
Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. I was looking into Valgrind to help improve my C coding/debugging when I discovered it is only for Linux – I have no other need or interest in moving … Read more
This question already has answers here: Closed 12 years ago. Possible Duplicates: What’s the use of do while(0) when we define a macro? Why are there sometimes meaningless do/while and if/else statements in C/C++ macros? do { … } while (0) what is it good for? I’ve seen some multi-line C macros that are wrapped … Read more
Can anyone explain how to create a header file in C with a simple example from beginning to end. 4 Answers 4
Through a little typo, I accidentally found this construct: int main(void) { char foo = ‘c’; switch(foo) { printf(“Cant Touch This\n”); // This line is Unreachable case ‘a’: printf(“A\n”); break; case ‘b’: printf(“B\n”); break; case ‘c’: printf(“C\n”); break; case ‘d’: printf(“D\n”); break; } return 0; } It seems that the printf at the top of … Read more
Today I was teaching a couple of friends how to use C structs. One of them asked if you could return a struct from a function, to which I replied: “No! You’d return pointers to dynamically malloced structs instead.” Coming from someone who primarily does C++, I was expecting not be able to return structs … Read more
I was browsing through some documentation and questions/answers and saw it mentioned. I read a brief description, stating that it would be basically a promise from the programmer that the pointer won’t be used to point somewhere else. Can anyone offer some realistic cases where its worth actually using this? 2 Answers 2
I’m trying to check whether a string contains a substring in C like: char *sent = “this is my sample example”; char *word = “sample”; if (/* sentence contains word */) { /* .. */ } What is something to use instead of string::find in C++? 12 Answers 12
When a pointer to a particular type (say int, char, float, ..) is incremented, its value is increased by the size of that data type. If a void pointer which points to data of size x is incremented, how does it get to point x bytes ahead? How does the compiler know to add x … Read more
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