I am trying to run a programme implementing a function with structures in c... which is:
#include<stdio.h>
#include<conio.h>
struct store {
char name[20];
float price;
int quantity;
[Code] .....
This is with Linux gcc
Code:
typedef struct _a
{
int id;
} a;
typedef struct _b
{
a my_a;
my_a.id = 1; // error: expected specifier-qualifier-list before "my_a"
} b;
I get error: expected specifier-qualifier-list before "my_a"
I must set the id for the kind of struct created inside the struct def because main() will be casting based on this id. Thats how I will know which structure b contains by it's id, there could be hundards of different structs with different values I will cast to the correct one and know it's members by it's id. How do I ?
Is it possible to assign a value to structure member inside the structure.like.....
struct control{
char tbi:2 =0;
char res:1 =0;
};
Code:
typedef struct token
{
int tokenType; // what token is that
int tokenCode; // the code of a function if applicable
char *tokenString; // Source token
double tokenValue; // if token is a number
[Code] .....
I got several warnings and erros, is it possible to declare a table like that ? What's the correct way to declare it ?
We had to write a "selling program for computers, laptops and tablets", which I did but for the extra credit, we have to have those three points in the application and I have tried but how to do the "extra credit" part, which I really need.
1.) A loop to prompt the user if they would like to place another order
2.) At least one user-defined function
3.) An enumerated data type, array or struct (structure)
I did one of these three, it's a "DO WHILE" loop asking users if they want to make another order, it's right at the beginning of the code.
Code:
#include <iostream>
#include <string>
#include <iomanip>
#include <fstream>
using namespace std;
double desktop();//function prototype
double laptop();
double tablet();
[Code] ....
Let me say I have a structure
Code:
struct time{
char hours;
char minutes;
char seconds;
char dummy;
};
I have kept dummy as the data to be aligned.I will update hours, minutes, and seconds , but will not use dummy in any case. If I don't initialize 'dummy' does it make any errors ? Do I need to initialize hours, minutes, seconds as well before I use the structure ? If so is there any particular reason ?
I want to define enumeration inside a structure and use it in some other file
for eg
header.h
typedef struct dummy {
typedef enum {
ZERO,
ONE,
MAX
} NUMBERS;
// some member variables
} DUMMY; // end of the structure
otherfile.cpp
in this file i want to access both enumerations(for eg) ONE as well as the type NUMBERS.
#include <stdio.h>
#include <string.h>
#define MAX 22
struct inven {
int Iid;
double uprice;
int uoh;
char name[MAX];
[code].....
doesn't seem to want to display the disp* fucntions at all
i had a structure as follows:
struct a{
int x;
struct b{
int y;
b *next;
}b;
};
when i try to access as follows:
struct a *a;
a->b=a->b->next;
i got the following error: base operand of ‘->’ has non-pointer type
I have some problem while allocating memory to a union inside structure. Below is the code i am using
ON SYSTEM1:
This works fine
ON SYSTEM2:
compiler complains saying "need structure or union type" while allocating MYSTRUCT1.
If I change:
shreyas[0].UnionAttr.struct1 = (MYSTRUCT1 *) malloc (sizeof(MYSTRUCT1)
to
shreyas[0].UnionAttr->struct1 = (MYSTRUCT1 *) malloc (sizeof(MYSTRUCT1)
This compiler on SYSTEM2 is happy. but second way does not look correct to me and compiler on system 1 complains about it. Which is the correct way to allocate memory?
If first one is correct then what should i look in for to avoid this error? Could this be an issue with compiler on SYSTEM2? If i use second method on SYSTEM2 code segfaults during malloc.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct mystruct1 {
int a;
int b;
[Code] ....
I have a question regarding composition and accessing members "deep" inside the composed structure. For example;
class A {
private:
int m_myInt;
public:
int myInt() const {return this->m_myInt;};
void myInt(int newInt) {this->m_myInt = newInt;};
[Code] ....
Now, from somwhere I have access to an object of type B where I want to update the A::m_myInt. How would you do this without "breaking" the whole purpose of private/public members?
B myB;
myB.m_a.myInt(3); // Not allowed, and not desireable
I thought about implementing access through functons kind of like;
A & B::a() {return this->m_a;};
myB.a().myInt(3);
but I'm worried that this exposes my B::m_a-object too much. This would allow
myB.a() = A();
, right?
The following is a more desireable way of acces, but doesn't work for updating;
A const & B::a() {return this->m_a;};
myB.a().myInt(3); //Disallowed? myInt(int) is non-const.
What about this? Is this a good way of doing it?
class A {
private:
int m_myInt;
public:
int myInt() const {return this->m_myInt;};
[Code] ....
I guess it works? It would lead to a lot of data shuffling in case of larger sub-components.I would really like to do the following without exposing my components so much:
B myB;
myB.a().myInt(3);
Can it be done?
I want to know
prog1.c
#include<stdio.c>
static int c=6;
int main() {
/*code*/
}
prog2.c
#include<stdio.h>
int main(){
static int c=10;
}
what would be the difference between these two program in the fuctioning of static keyword ?
Why doesn't this compile?
struct hi(){
void other();
}histructure;
void hi::other(){
std::cout << "Hi!" << std::endl;
[Code] ....
Makes no sense the structure is written before the structure member function is called so why is there compile errors ??...
After i set the value in the first structure owners name, i set the cats name equal to it. but when i change the value in the first structure it doesn't change the value in the second structure.
So i need the dogs owners name to be equal to the cats owners name
So if i change the value of the dogs owner it also changes the value of the cats owner.
Code:
#include <stdio.h>#include <stdlib.h>
#include <string.h>
//stucture
struct structDog {
[Code] ....
I'm having trouble understanding why after x.w is defined x.b[1] gets defined over top of it.
Leaving me with an output reading;
1d
1d3f
Rather than;
1d
1c3f
#include "stdio.h"
#include "conio.h"
int
main() {
union{
[Code] ....
I am getting this error while trying to compile my program:
It says that my variables "nome, cognome, eta..etc" are being used for the first time in my "inserisci" function.
I tought that I could just declare them as global in my structure like I did in my code, but apparently this doesn't work.
Do I really need to declare them again outside of my structure? Isn't there another way?
Here is my code:
#include <stdio.h>
#include "readline.h"
void inserisci(void);
struct impiegato{
char nome[20];
char cognome[20];
int eta;
[code].....
Example :
Code:
struct x {
int v[4];
};
const x test = { 0, 1, 2, 3 };
Why can I do this? How does the compiler know to write to this in the proper way? I get that v would be contiguous. Does that have something to do with it?
how I can create a structure that pointing to another different structure. And also passing structure to function.
View 3 Replies View RelatedMy program is designed to read input from the user and then store that input in a structure variable. Whenever i use the cin.getline() function, it comes up with a semantic issue. Here is the code:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
const int DESCRIPTION_SIZE = 100, DATE_SIZE = 20;
struct inventory {
string description[DESCRIPTION_SIZE];
[Code] .....
I left out the other functions. The error reads "no matching member function for call to 'getline'.
I am not able to assign value into struct addrinfo variable through struct sort_result structure variable.
struct addrinfo {
int ai_flags; /* Input flags. */
int ai_family; /* Protocol family for socket. */
int ai_socktype; /* Socket type. */
int ai_protocol; /* Protocol for socket. */
[Code] ....
I created a class (let call it X) which contains the structure to store the data from my data base. Them I have a class (call Y) which will contain a list for each row in my data base. Third, I have a class with thousands variables (Z). What I am trying to do is to take the list of objects (Y) that contains the data to initialize Z. What I want to now if I can do something like that.
Imaging that one of my rows contain the following data:
Type Nameofvariable etc...
"static const double; MNFAIL ; 0; 0; 0,25"
In my list I have a node with contain this data
I want to use the field Nameofvariable to initialize the variable called MNFAIL contained in my class Z.
Is it possible in C++
I'm trying to call a function via a function pointer, and this function pointer is inside a structure. The structure is being referenced via a structure pointer.
Code:
position = hash->(*funcHash)(idNmbr);
The function will return an int, which is what position is a type of. When I compile this code,
I get the error: error: expected identifier before ( token.
Is my syntax wrong? I'm not sure what would be throwing this error.
"
#include <stdio.h>
struct datastructure {
char character;
};
void function(struct datastructure** ptr);
[Code] ....
These codes give these errors:
error: request for member 'character' in '* ptr', which is of non-class type 'datastructure*'
error: request for member 'character' in '* ptr', which is of non-class type 'datastructure*'
These errors are related to
"
*ptr->character='a';
printf("Ptr: %c",*ptr->character);
"
I want to access "character" data inside the structure "trial" by a pointer to pointer "ptr" inside function "function",but I couldn't find a way to do this.
I want to return value from user defined function to main.
Code:
#include <stdio.h>
int mult ( int x, int y );
int add(int x, int y);
int loop (int y);
int main() {
[Code] ......
so i have two classes ( main and another one ask ) in main i have defined 3 arrays (char drivers[250] ,offences[250] , owners[250]) and also included their pointers ( char *drivers_ptr,*offences_ptr,8owners_ptr)my problem is that i need to set values (actually 1 string of 250 chars to each of these arrays BUT from the class ask without making these arrays global -as this is prohibited by my university exercise !- )
so my question is how will i manage to save data to the arrays that i have defined in main using their addresses(through the pointers of each one that i have passed to the ask class) from the ask class ?
I am a beginner with C++, taking a class right now. The lab this week is to create a user defined class and have it accesses in a separate .h header file from the main.
I think I'm finding my way through it, but I'm getting a complie error that makes no sense to me:
1> Resistor.cpp
1>c:users omdocumentsschoolcomp 220week 2lablab 2.2lab 2.2
esistor.h(11): error C2146: syntax error : missing ';' before identifier 'resistor'
1>c:users omdocumentsschoolcomp 220week 2lablab 2.2lab 2.2
[Code] .....
Here is the first portion of the .h file:
#include <iostream>
#include <iomanip>
#include <Windows.h>
#include <math.h>
#include <string>
class CResistor{
double res1, res2, res3, percentage, Nominal, Tolerance;
[Code] ....