C++ :: Structs And Arrays
Jul 30, 2014If i want to input (FROM A FUNCTION) information into a struct:
* How do I define/ call/ prototype that function.
* How do I check if that array inside the function is empty?
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C++ :: Outputting Data From File Into Structs And Arrays Of Structs
Apr 15, 2013I am having a lot of trouble being able to get data from a file and input it into given structs and arrays of structs and then outputting the file. We are given a file that contains 96 lines and looks like this:
Arzin, Neil
2.3 6.0 5.0 6.7 7.8 5.6 8.9 7.6
Babbage, Charles
2.3 5.6 6.5 7.6 8.7 7.8 5.4 4.5
This file continues for 24 different people and then repeats with different scores (the second line).
The first number, in this case is 2.3 for both people is a difficulty rating. The next 6 numbers are scores.
We are given this data in order to set up our structs and arrays and my code:
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <cmath>
using namespace std;
int main () {
ifstream inFile;
inFile.open("C://diveData.txt);
[Code] .....
C :: Structs With Double Arrays
Apr 19, 2014The main is not working properly, I get strange missing parenthesis notices and array errors which I am not understanding. How to identify the errors. Functions are included.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int menu ();
double change_value (double * value);
[Code] ......
C++ :: Using Structs And Arrays For Grading?
Jul 3, 2012Write a program for the following problem. You're given a file that contains a collection if IDs and scores (type int) for an exam in your computer course. You're to compute the average of these scores and assign grades to each student according to the following rule:
If a student's score is within 10 points (above or below) of the average, assign a grade of satisfactory. If a studnt's score is more than 10 points above average, assign a grade of outstanding. If a student's score is more than 10 points below average, assign a grade of unsatisfactory.
The output from your program should consist of a labeled three-column list that shows each ID, score, and corresponding grade. Use a struct to store each student's data and an array of structs to store the whole class. The struct should have a data member for id, score, and grade.
I was given the following file grades:
3313904258647075100
568888487970797094
4700504489737073100
956188698887846398
31999669100908867100
376878578059571560
82917256708274983
7754766293100784158
81469468999493954
2106984796947027100
So far, I have this much, but the output is all wrong. I also haven't tackled the grade part yet.
Code:
//grader.cpp
//Grades
#include <fstream>//required for file streams
#include <iostream>//input/output
#include <cstdlib>//for definition of EXIT_FAILURE
#include <string>
#include <iomanip>
using namespace std;
#define inFileGrades "grades.txt"//grades
[code]....
C/C++ :: Function Not Returning Values - Structs In Arrays
Feb 25, 2015I wrote this code for a homework assignment, everything runs fine but the function void percent_votes (line 66) isn't calculating properly, it outputs 0.00 for each value. I have tried everything I can think of to try and make it work.
Here is the assignment: Write a program that allows the user to enter the last names of five candidates in a local election and the number of votes received by each candidate. The program should then output each candidate's name, the number of votes received, and the percentage of the total votes received by the candidate. Your program should also output the winner of the election.
Here is the code I have written:
#include <iostream>
#include <string>
#include <iomanip>
#include <cmath>
[Code].....
C/C++ :: Pointers And Structs
Dec 14, 2014What the second print statement prints
main() {
struct s1{
char *str;
int i;
struct s1 *ptr;
[Code] .....
I executed the code and the output was some number(for second printf) but it should print a string.
C++ :: Nested Classes And Structs
Mar 12, 2014I'm working on a project involving nested classes and structs like this:
Code: class A {
public:class B {
public:f()
{A::C* iCanDoThis; //no errors.
iCanAlsoDoThis->root->.... //this also works fine.}private:A::C* iCannotDoThis //this is what I would like to do.
Has errors
A* iCanAlsoDoThis;};private:struct C
{..data..};
C* root;};
Is it possible make a pointer to struct C a private member of class B?
C :: Using Fwrite And Fread On Structs
Jul 20, 2014I'm currently working on a program that writes an array of struct to a file and then read back the data from the file to another array of struct. At the bottom is an image of my result.
My goal is to end up with two identical struct arrays but my program fails to do this. My struct have to members: ID and kind (of animals in this case). I declare my first arraystruct africa[] with "monkey" and "giraffe" with their respectively IDnr: 112 and 555. I stream this data to a file and read read them back to the arraystruct get_animal[]. Simply I want the get_animal[] to be identical with the africa[] when the program is over, but that is not so. According to my result(bottom image) it display:
112, monkey (get_animal[0])
112, monkey (get_animal[1])
meaning that get_animal[0] is identical to africa[0] get_animal[1] is also identical to africa[0]
but why? I want get_animal[1] to be identical with africa[1]. meaning I want the result to look like this:
112, monkey
555, giraffe
I've also made the program to print the parameters of my fwrite/fread calls. Why is the 3rd parameter = 1 meaning that only 1 element will be read/written when my program just read/write 2 elements?
Code:
main(){
FILE *fp;
struct animals
{
int id;
char kind[20];
} africa[1] = {{112,"monkey"}, {555,"giraffe"}};
}
[code]....
C++ :: Structs And Incrementing Output
Apr 3, 2013How would I be able to have this display the rest of the households without having to have 13 separate cout lines(one for each household)? In other words, how can I set it up to increment the output?
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
struct Household {
int idNumber;
int income;
[Code] ....
C++ :: Passing Structs And Functions All In Same
Mar 8, 2013I think i am getting confused with passing structs and functions all in the same...When I run through the program (it compiles), the functions that add coins do not add, but rather just replace an old value with a new one.
#include <cstdlib>
#include <iostream>
using namespace std;
struct coinbox {
[code].....
C++ :: Array Of Structs With Constructor?
Apr 1, 2013I can't seem to remember everything I should about constructors. I'm looking for a way to create an array of structs, using a constructor. My code should explain.
struct myStruct
{
private:
int structInt1, structInt2;
[Code].....
C++ :: Using Structs To Define A Function
Sep 27, 2013What I'm trying to do :
struct foo {int x; int y;};
foo function_example(int x, int y) {
foo temp;
temp.x = x;
temp.y = y;
return temp;
}
Works as is, however when I try doing it through seperate class files :
//header file for class example_class
struct foo {int x; int y;};
foo function_example(int x, int y);
//source file for example_class
foo example_class::function_example(int x, int y) {
foo temp;
temp.x = x;
temp.y = y;
return temp;
}
I get an error telling me that foo is undefined, and that declaration of function_example(int x, int y) is incompatible with the declaration of it in the header file.
C++ :: Pointers To Array Of Structs
Feb 14, 2013I have an assignment where I need to use pointers to do a few things and I am a little confused on the syntax of it all. My question is how do you use a pointer to point to an array of structs.
For example
struct info{
char firstName[15];
char lastName[15];
};
main() {
info person[4];
cout << "The third letter of the second persons first name is: "; // ?????
}
how would I define a pointer to point to the third letter of first name the second person in the "person" array.
C++ :: Filling A Vector With Structs
Feb 1, 2013How to fill a vector with structs that are read in from a separate file. Each line in the file would read for example "Doe John M 26" for the name of the person, gender and age. I just need to get pointed in the right direction so I can get this started.
View 2 Replies View RelatedC++ :: Binary File And Structs
Sep 5, 2014What is the difference between reading from binary file between the following way:
struct aStrct{
int number;
}vars[];
while(file.good())
file.read((char*)&vars, sizeof(aStrct))
And
while(file.good())
file.read((char*)&vars[i], sizeof(aStrct))
i++;
C++ :: How To Qsort Array Of Structs By One Of Its Members
Mar 31, 2013I am versed in qsorting struct members within a struct instance, as in the example below:
Code:
#include <iostream>
#include <stdlib.h>
using namespace std;
struct item_database {
[Code]....
What I CANT do however is to sort an array of structs by one of its members. This is a complete different problem even if it sounds similar.
In other words, the problem is this; Say we have a struct:
Code:
struct item_database {
int key;
string token;
};
Then we declare an array of this struct in the heap:
Code: item_database *idptr = new item_database[700000]; and initialize its values.
How would one go about sorting this heap array of structs by its member function "token"?
I used the following call to qsort (standard library) and call to the compare function but it doesnt work:
Code:
qsort (idptr, 1000, sizeof(string), compare);
Code: int compare (const void* a, const void* b){
if (*(char*)a >= *(char*)b)
return 1;
else
return -1;
}
Or in more lamens terms say we have the following stuct instances:
Key: Token:
1 Hello
2 World
3 How
4 Are
5 You
Then I need those structs to order according to token (alphabetically, increasing or decreasing depending whats in our compare function).....
C :: Passing A Pointer To Array Of Structs
Nov 20, 2013what I am trying to do is to pass to a function the address of an array of structs, so I can later modify the items within the struct, within the array
Code:
typedef struct { //A struct of name auctionint bidder;float bid;} auction;
void myFunction (auction * auctionItem[]){(*aucItem[x]).bid = y;(*aucItem[x]).bidder = z;}
int main(){auction theItems[10];
myFunction(theItems);} Where x, y, and z can be any number.
When I try to run my code the IDE (I'm using Code::Blocks 12.11) does not give me any errors, but it does give me a warning:
warning: passing argument 3 of '<function name>' from incompatible pointer type [enabled by default]
and the note:
note: expected 'struct <struct name> **' but argument is of type 'struct <struct name> *'.Also, when I run the program, it will crash and return garbage.
C :: Adding Elements To Array Of Structs
Mar 6, 2015I have a structure product_array *pa that contains a pointer *arr to an array of structs and count that adds 1 when a new product is added (set to NULL initially). I have to write a function which adds a new product entry to that array. One product entry has *title, *code, stock and price parameters. The array is dynamically allocated and I’m supposed to:
1. Reallocate space for array.
2. Update product_array.
3. Initialize it.
Also, code should be truncated to 7 characters.Products can be added multiple times, so the initial size is unknown.
Code:
void add_product(struct product_array *pa, const char *title, const char *code, int stock, double price)
{
for (int i = 0 ;; i++){
pa->arr = realloc(pa->arr, sizeof(struct product_array));
[code]....
C :: Structs - Implement In With Pointers And Functions
Feb 23, 2013I have a struct and I want to implement in with pointers and functions.
What is the corect syntax? For example:
Code:
typedef struct XYZ
{
int x;
int y;
int z;
}XYZ_t;
int func( using the XYZ_t struct)
[Code] .....
C :: Setting Values For Array Of Structs
Dec 18, 2013How do I set all of these string and double value(s) to 0?
Code:
#define MAXcharacters 12
#define MAXaccounts 100
struct Records {
char userid[MAXcharacters + 1];
char password[MAXcharacters + 1];
double balance;
};
[code]...
C :: Dealing A Deck Of Cards Using Structs?
Sep 9, 2013I have a deck of 108 cards inside a 2D array and want to deal these card by 7 to 4 player. Each player had a id. The player and id are stored in a file while i've read in array each. Now I have to deal the cards.
Code:
struct card{
char color;
int rank;
char action[24];
char location[108]; Code: struct players{char name[10];
int id[5];
char hand;
};
C++ :: Memory Addresses Of Pointers To Structs
Apr 19, 2014I have this struct declaration to create a linked list
struct node {
string y;
node* next;
};
If I create a linked list of 3 nodes
A->B->C->NULL
A->y is "a"
B->y is "b"
C->y is "c"
Since they are consecutive in memory. How far apart are the strings in memory?
I tried doing something like
int n = &(head->next->x)-&(head->x);
The problem is that I got 6 while debugging and 2 otherwise.
C/C++ :: Create Growable Queue Of Structs
May 31, 2014I need to create a dynamically allocated, growable, queue of structs. I tried my best to do as much as I could. What's holding me up is the queue aspect of it.
#include <iostream>
#include <string>
#include <stdlib.h>
[Code].....
C/C++ :: Scanning CSV File Into Array Of Structs
Mar 18, 2015I need to scan a .csv file that contains the following info:
programming,03,60,141,01,W,2015
programming,03,60,141,30,W,2015
Algebra,03,62,102,02,S,2013
Religion,08,98,938,20,F,2014
So i made a struct:
typedef struct CourseInfo {
int courseID;
char courseName[50];
char courseCode[13];
char term[7];
} courseinfo;
Where course code is the 4 numbers after the name together and the term is the letter and year in the last two pieces of info. I got this to work:
int main() {
FILE *p;
p = fopen("input.csv", "r+");
if(p == NULL) {
puts("The file could not be opened");
[Code] ......
But lets say i dont know how many lines i have in my file and i want to count them and then use that size for my array so i tried this by:
int main() {
FILE *p;
int lines = 1;
char ch;
p = fopen("input.csv", "r+");
if(p == NULL) {
[Code] .....
But the second program is not working for unknown reasons. I do not get any errors but its not scanning the info because when i print the info later on it prints out random symbols.
C++ :: Singly Linked List Of Structs?
Mar 1, 2013I want to make a singly linked list of structs with a custom datatype. Sadly, I dont think I understand either.
#include <iostream>
using namespace std;
struct datatype
[Code]....
Basically, I cant figure out how to insert a strcut with a string, random ID number, and a random salary amount, into a linked list.
C :: Reading Text From A File And Trying To Set Names To Structs
Feb 5, 2013I am reading text from a file and trying to set names to structs. Here is the input file
Code:
2
3
Quincy Richard Steven
Donna Elizabeth Francine
5 2 9
4 5 7
5 9 6
4 6 5
7 8 9
6 9 1
Code:
#include <stdio.h>
#include <stdlib.h>
#define MAX_CHARS 20
// Structure that has 2 properties: name and scores.
struct person
[Code] ....
In the nested for-loop it should read in the name of each men and print it out, like so:
Code: Quincy Richard Steven
However it is printing out:
Code: QuincyRichardStevenDonnaElizabethFrancine