There’s several problems with your code. First, the swap function doesn’t work. You’re swapping the values of the pointers that are local variables inside the function, you’re not swapping the array elements they point to. You need to indirect through pointers to get the values. int temp1 = *a; *a = *b; *b = temp1; … Read more
It is completely up to the implementation. For example, const data on bare metal ARM uCs is stored in the FLASH memory. You can write to there but it will have no effect at all. Hosted systems will behave differently depending on the OS, its version and hardware. How can I overwrite a const block … Read more
There is none. Once the array-to-pointer conversion happens, the size information is gone. If you need it, you have to pass the size as a separate argument. Since pArr is a pointer, sizeof(pArr) gives the size of the pointer. Your pointers seem to be double the size of ints; that is the case on x86-64, … Read more
Exception thrown at 0x0F640E09 (ucrtbased.dll) in ConsoleApplication5.exe: 0xC0000005: Access violation writing location 0x014C3000? solved Exception thrown at 0x0F640E09 (ucrtbased.dll) in ConsoleApplication5.exe: 0xC0000005: Access violation writing location 0x014C3000?
In your first example, you MUST pass a char pointer for the “%s” modifier so it is actually the way it has to be, you would of course know that if you read the appropriate documentation, like e.g. The C Standard. The second one, is wrong. Because it would invoke undefined behavior. To print the … Read more
Your example code should not give any errors as was proved by Robert Crovella. I looked at your original code and found a misaligned parenthesis cause by that first “for” loop. Good luck… 0 solved CUDA: Using a global thread index with shared memory won’t work [closed]
fix like this #include <stdio.h> #include <stdlib.h> #include <string.h> #define BUFF_SIZE 32 #define STRUCT_SIZE 512 struct info { char name[BUFF_SIZE]; char stAddress[BUFF_SIZE]; char cityAndState[BUFF_SIZE]; char zip[BUFF_SIZE]; }; void selectionSort(struct info *ptrStruct[], int size);//! int main(void){ int count, size;//! char buffer[600]; struct info *ptrStruct[STRUCT_SIZE]; for (count = 0; count < STRUCT_SIZE; count++){ ptrStruct[count] = (struct info*) … Read more
This dereferences an uninitialized pointer, resulting in UB: *p = i; You probably want this instead: p = &i; solved pointer behaviors in c++
why we need pointer variables… No, we don’t need pointer variables until… we need one. In other words, there are many cases (or algorithms) which don’t need pointers. But soon or later you realize that pointers are needed. Well, pointers contain values, which are different from integers, different from floating point numbers and so on. … Read more
Let us assume that msg->dup() returned void * — that is, a pointer to void, which means a pointer whose type the compiler doesn’t track. But you may know, e.g. because of documentation on that function, or because certain preconditions have been met, that msg->dup() will return a pointer to CMessage. Before you can use … Read more