[Solved] Error running program – C [closed]
Both what1() and what2() are modifying strings passed as literals, that’s undefined behavior since such strings can be stored in read-only memory. 1 solved Error running program – C [closed]
pointers
[Solved] C: Variable is uninitialized for linked list
@Sourav Ghosh have already explained what was wrong with your code and also suggested one way to solve it. Here is another way. Instead of passing current and head as variables to be changed inside the function (i.e. as pointer-to-pointer), I would recommend that you use the function return value. In that way you don’t … Read more
[Solved] Why do I have to skip the month of february in the for loop and use mes->fevereiro[j] instead of mes->meses[1][j]? [closed]
Why do I have to skip the month of february in the for loop and use mes->fevereiro[j] instead of mes->meses[1][j]? [closed] solved Why do I have to skip the month of february in the for loop and use mes->fevereiro[j] instead of mes->meses[1][j]? [closed]
[Solved] Advanced pointer typecasting in C/C++ [closed]
The memory simply contains bytes of data. It is up to you how you interpret this data. Your buffer may be interpreted as int. For example: char buffer[] = {1, 2, 3, 4}; int number = *(int *)buffer; Running the code on an Intel x86 processor would result in number having the value of 0x04030201, … Read more
[Solved] C++: Update to memory location using pointer is lost [closed]
This is bad: void TestLocalQueue::putMsg(){ ControlCommand cc; cc.setDynamic(“target”); cout<<“Setting Dynamic context \n”<<endl; localQueue->put(&cc ); The localQueue->put function stores the pointer you give it into the queue. However cc‘s lifetime is only for the duration of the putMsg function, so when this function exits you will have a dangling pointer. To fix this you could either … Read more
[Solved] Make a new pointer in a loop C
i and id are both local variables with automatic storage (commonly referred to as on the stack). No new instances are created upon each iteration of the loop, the same space is reused and a new value is stored in id, hence the same addresses printed by printf. Note that the value of id is … Read more
[Solved] Linked List private pointers C++ [closed]
private members, pointers or otherwise, are data that the object either does not want messed by anyone else with or wants to know if someone messed with them. Setter and getter methods allow access to the private member, but in a controlled manner. For example if you have a private integer that under no circumstances … Read more
[Solved] How a pointer to a string works in a function?
Snippet 1 char a[200],*p; Defined a block of 200 characters ,a, and a pointer, p, to a block of one or more characters. gets(a); // cin.get(a,200); Read some user input into memory block a p=a; Points p at block a. p can now be used as a reference to the same thing as a strcpy(p,p+1); … Read more
[Solved] I’m just beginning to learn C: Can someone explain what the pointers and typecasting are doing in this code? [closed]
The snippet char *encrypt(char *string, size_t length) { } defines a function named encrypt, which takes a char * and a size_t as arguments, and returns a char *. As written, the function body is empty and will trigger at least one diagnostic because it isn’t returning a value. It looks like it’s meant to … Read more
[Solved] How can i compare three strings using only one pointer and nothing else
I want to have a program in C that reads 3 numbers and prints the bigger one, using only one pointer and no more variables. #include <stdio.h> #include <stdlib.h> int main(void) { int *p; p = malloc(sizeof *p); // assume it worked if (scanf(“%d”, p) != 1) /* error */; // read 1st number printf(“%d\n”, … Read more
[Solved] Array and pointers in c++ [duplicate]
I often hear that the name of an array is constant pointer to a block of memory You’ve often been mislead – or you’ve simply misunderstood. An array is not a constant pointer to a block of memory. Array is an object that contains a sequence of sub-objects. All objects are a block of memory. … Read more
[Solved] Pointer gives me the address rather than the value;
OK, now I think you’ve finally posted the code that has the problem class ZombieLand : public Singleton<ZombieLand> { DECLARE_SINGLETON(ZombieLand); public: MachineState* world[19][19]; bool map[19][19]; MachineState* getField(int x, int y) { return world[x][y]; } void setWorld(MachineState state) { world[state.x][state.y] = &state; map[state.x][state.y] = true; } }; This is undefined behaviour because you are saving the … Read more
[Solved] What is the difference between char *ptr = “hi”; int *ptr = “100”? [closed]
Unless you’re really know what you’re doing and have some special plan, what you’re doing does not make sense. int *ptr = “100” is basically just a shortcut for this: char *tmp = “100”; int *ptr = tmp; To avoid the warning, you need to do this: int *ptr = (int*) tmp; But don’t do … Read more
[Solved] is it possible to set the value of allocated memory with loops?
When you assign to a pointer, you need to dereference it, like this: *pointer = i + ‘a’; Instead of: pointer = i + ‘a’; Otherwise, all you’re doing is changing the value of the pointer itself, not the value of the memory location it is pointing to. This explains your error: you’re trying to … Read more
[Solved] Copy array of strings to array of string pointers
To understand what is happening under the hood you must understand the pointer and value semantics of for range construct in go. It is clearly explained in this ardan labs article emails := []string{“a”, “b”} CCEmails := []*string{} for _, cc := range emails { p := &cc fmt.Println(cc, p) CCEmails = append(CCEmails,&cc) } The … Read more