Advertisements I found the following answer: Convert void* to double However, I am getting segmetation fault. Why is that? Code: void * p = (void *) 1234; double n = *(double *)p; >Solution : Pointer p is assigned to address 1234 that you chose at random?. You are then referencing a random address. It does… Read More Casting a void * to a double segmentation fault
Advertisements #include <stdio.h> void main(){ int *i = (int *) malloc(12); *i[0] = 1; printf("%d", *i[0]); } i is supposed to be a pointer. So then why doesnt this code work? and why does this code 👇 work? void main(){ int *i = (int *) malloc(12); i[0] = 1; printf("%d", i[0]); } >Solution : When… Read More while allocating/printing why don't I have to dereference an array pointer in c?
Advertisements I have been looking at c pointer to array of structs , and trying to apply it to my example. I arrived at this code snippet, which compiles fine: #include <stdio.h> enum test_e { eONE, eTWO, eTHREE, }; typedef enum test_e test_t; #define NUMITEMS 12 extern test_t my_arr[NUMITEMS]; test_t (*my_arr_ptr)[NUMITEMS]; test_t my_arr[NUMITEMS] = {… Read More Possible to Initialize pointer to array of typed variables?
Advertisements Passing a non-const pointer to a function which expects a const pointer usually raises no warning (makes sense, the function promises to be "nicer" than the caller would expect), but a non-const pointer-to-pointer to a function expecting an const pointer-to-pointer does raise a warning (with gcc -Wall, 11.4) and I’m struggling to think why… Read More Incompatible const pointers
Advertisements I am self learning C++ and I found my self on the Pointers section of C++. To my understanding the pointer allocates the value of a variable to a memory. But I came across on this problem which the answer is 588. And I cannot figure out how this number came up. Can someone… Read More Pointers explanation in C++
Advertisements Just trying to (re)learn C and struggling with some basic concepts. I’ve took a look this thread: How to memset an array of bools?. According to that, it seems i may initialize a boolean 2d array like the following: size_t size = sizeof(bool[4][3]); bool (*ary)[4] = malloc(size); memset(ary, false, size); The problem i see… Read More What's the best way to initialize a dynamically allocated boolean 2d array?
Advertisements I’m passing the Test variable that I declared in my main function to tf function. If I make a change to the argument in tf, the actual Test variable changes. Is there any way to prevent this without creating another variable in the tf function? The Code #include <stdio.h> void tf(char *argument){ argument[0] =… Read More Function changes the value of the given argument
Advertisements Why does the following code output two different pointer addresses for one of the Timer._d objects in the vector? This is a minimal example of the issue I’m seeing — see below for a complete picture. #include <cstdio> #include <vector> #include <iostream> struct Data { int duration = 0; }; class Timer { private:… Read More Why are is the address of a pointer different when accessed in two different ways?
Advertisements This is my example code: #include <stdio.h> void Func(int a[], int b) { a[b] = 1; b += 5; } int main(void) { int a[10]; int b = 0; printf("%d\n", b); Func(a, b); printf("%d\n", a[0]); printf("%d\n", b); } And I want the program to print: 0 1 5 I’ve tried changing the function by… Read More How to change the value of a variable passed as an argument and also use the value for an array
Advertisements I’m practicing pointers right now. The task is simple, count the number of instances of the letter c in an array and print the amount of times it occurred.I assigned a pointer to a counter variable in a function outside of main. For some reason, my program doesn’t count when I use *count++; #include… Read More My program adds to the counter variable when I use "count+=1" and doesn't when I use "count++"