struct

问题 I need your help at understanding how bit fields work in C programming. I have declared this struct: struct message { unsigned char first_char : 6; unsigned char second_char : 6; unsigned char third_char : 6; unsigned char fourth_char : 6; unsigned char fifth_char : 6; unsigned char sixth_char : 6; unsigned char seventh_char : 6; unsigned char eigth_char : 6; }__packed message; I saved the size of the struct into an integer using sizeof(message). I thought the value of the size will be 6

问题 I've already asked 2 questions kind of related to this project, and i've reached this conclusion. Writing the size of the Struct to the file , and then reading it back is the best way to do this. I'm creating a program for a homework assignment that will allow me to maintain inventory. I need to read / write multiple structs of the same type to a file. The problem is... this is really complicated and i'm having trouble wrapping my head around the whole process. I've seen a bunch of examples

问题 I am learning DSA , Linked List , new to C++. My linked list is of exception. Error Info: It is much longer than it should be. Here is my code: define struct ListNode // Definition for singly-linked list. struct ListNode { int val; ListNode *next; ListNode(int x) : val(x), next(NULL) {} }; get Intersection of Two Linked Lists ListNode * Solution_three :: getIntersectionNode(ListNode *headA, ListNode *headB) { ListNode * p_one = headA; ListNode * p_two = headB; if (p_one == NULL || p_two ==

问题 I have defined a structure with three integers, then created a dynamic array of the structure. Later in the code, I want to increment some of the integer values in the structure: typedef struct { integer tc; integer pass; integer fail; } score_t; score_t scorecard[]; integer tc_count; initial .... scorecard = new[`MAX_TC]; .... scorecard[tc_count].fail = 0; .... scorecard[tc_count].fail++; However, when I compile in Aldec Active-HDL I get the following error: Error: VCP2615 ../../../m3_test

问题 I want all threads to read from the same structure. I did it in the past by adding threads inside the loop which reads from the structure but this time I need the structure to be opened inside void "dowork" as my example shows. I have the following code: struct word_list { char word[20]; struct word_list * next; }; struct word_list * first_word = NULL; //other function which loads into struct is missing cause it's not relevant //in main() pthread_t thread_id[MAX_THREADS]; int max_thread = 10;

问题 Good morning everyone! I'm with a new problem here. I have to write down a data that comes from a struct that I declared in my sistem. The struct I created has only two fields and I use to to later conevrt it into bytes. [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)] public struct MyStructData { public short Id; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 20)] public string Name; } I convert this struct in bytes with the following code: private byte[] getBytes

问题 Here is part of my code. I would like to initialize only the arraylist[0] as arraylist[0].x = 0 and arraylist[0].y = 0 . I do not need to initialize the rest of the struct array. How can I do it? Thank you. #include <stdio.h> struct example { int x; int y; }; struct example arraylist[40]; int main(int argc, char *argv[]){ printf("%d\n %d\n", arraylist[0].x, arraylist[0].y); return 0; } 回答1: You can initialise any particular element of the struct array. For example: struct example arraylist[40

问题 I am trying to dynamically reallocate memory for an array of structs (actually an array each of 2 structs but 1 included here for simplicity) that is being read from/to a file or inputted by the user. typedef Struct { char surname[21]; char firstname[21]; char username[21]; ... } User; ...in main(): int size = 0; /* stores no. of structs */ User* user_array = (User *) calloc(1, sizeof(User)); if(user_array == NULL) { printf("Cannot allocate initial memory for data\n"); exit(1); } else size++;

问题 I am trying to dynamically reallocate memory for an array of structs (actually an array each of 2 structs but 1 included here for simplicity) that is being read from/to a file or inputted by the user. typedef Struct { char surname[21]; char firstname[21]; char username[21]; ... } User; ...in main(): int size = 0; /* stores no. of structs */ User* user_array = (User *) calloc(1, sizeof(User)); if(user_array == NULL) { printf("Cannot allocate initial memory for data\n"); exit(1); } else size++;

问题 I've been doing some reading about bitfields in C, how the C standard doesn't enforce any particular ordering of the fields in a machine word, and so on. I hope this question appropriately fits the format of SO. My question is whether my struct (definition following) will actually perform in the way I expect. Here's the definition I came up with, and then I'll discuss what I want: typedef enum { STATE_ONE, STATE_TWO, STATE_THREE, STATE_FOUR } __attribute__ ((packed)) State; typedef struct