I'm confused about accessing elements from arrays. Supposed I have an array of pointers to char:
char *names = { "John", "Rose", "Steven" };
To access one of the strings, should I use names[ 0 ][ i ], where i is an index in the set ( 0, 1, 2 ), or should I use names[ i ]? I would think it would be the first option, because this array has 1 dimension that contains others arrays, right?
I want to access the elements of my array dynamically. So far I've only figured out how to do this manually. if I tried it like this my code would work but there should be a better way right?
View 10 Replies View RelatedI am trying to retrieve the elements in an array to print them. I am pretty sure I have everything right, but it is not working. There are 5 values in the array {3, 4, 10, 5, 6}, but the first two elements (supposed to be 3,4) are coming out a 0,-2654238590. The last three elements are coming out correct.
void addDynArr(DynArr *v, TYPE val) {
/* FIXME: You will write this function */
assert(v != 0);
//resize if necessary
if(v->size >= v->capacity)
[Code] ....
I've been working for some number of days on this code to take information about movies from both a file and the user, store the infos in an array of structs, and at the end, write all the info out to a file. I'm having some problems with an error message reading:
"prog.c:102:11: error: subscripted value is neither array nor pointer nor vector"
this error occurs in many lines (which I will label specifically below -- they are everywhere where I am trying to access/modify an individual element of a struct element of the array).
A few examples of where I am having the problems are lines:
39, 52-55, 70, 72, and 86 (and more of the same exact variety).
I am obviously rather systematically doing something wrong, but I am quite certain all of these are the exact same mistakes.
I pull up also 2 or 3 other errors, but I don't think they are related and should be able to fix them quickly once I work out this conundrum.
#include <string.h>
#include<stdlib.h>
#include <stdio.h>
int moviecount =0;
typedef struct{
int year;
[Code] .....
so lets assume i have a nested vector in a set or vice versa o in a more general form a container in a container example...
Code:
std::set<vector<int> > my_tuple;
How do i access individual elements of lets say the first vector in the set! Or the last element in the 3rd vector?
Code:
int arr[10];
int* p = arr;
int (*p2)[10] = &arr;
So, pointer p is a pointer to an array, I can use it to access elements of arr as in *(p+5).
Pointer p2 is a pointer to an array of ten integers. What is it for, how can I use it to access elements of arr?
I came across the below code snippet in a project and was not sure how value of variable "response" is computed. Here as we can see, pic_data holds two one dimensional arrays but "response" access both the single dimensional array as two dimensional array.
Code:
#define MAX 100
#define MAXBUF 100
u32 response;
u32 index;
}
[code]....
How do i access the private array? I tried this and it's not working. Want i want to do is create class object in main and pass the string to constructor, and set m_make, m_model to that string. Then call the member function to output that.
const int BUFLEN = 256;
// class declaration
class CVehicle
{
[Code].....
We are learning how to use composition. In this project there is the Main (), resistor .cpp and .h, capacitor .cpp and .h, and filter .cpp and .h. I have 4 arrays built in the resistor.cpp that I want to print through the main(). I put the arrays in the constructor and have watched them initialize with the proper values, but as soon as the program leaves the constructor the values are wiped away and the elements are left with the value " -858993460 " in all of the them.
Here is the code:
Filter Main()
#include "Capacitor.h"
#include <conio.h>
#include "Filter.h"
#include <iostream>
#include "Resistor.h"
#include <windows.h>
#include <iomanip>
[Code] .....
I'm working on a project where I have the user enter storm data about hurricanes for multiple seasons. I need to make separate arrays for:
1. the month, wind speed, and min. press.
2. the category of the storm
What I'm having trouble understanding is how to make the software take an input, assuming from a scanf, and put it in an array. Then taking that value and output-ing it back out when needed.
So here is piece of my code. Note: Disregard the commented sections of the code, my current project is building off a previous one, where in the last project we were using loops, now we are using arrays.
case 1:
{
if (year > 0) //begins counting
{
/*num_trop_storms = 0*/ num_hurricanes = 0, year = 0, wind_speed = 0,
hcat1 = 0, hcat2 = 0, hcat3 = 0, hcat4 = 0, hcat5 = 0, hrun = 1, totalhurr = 0;
knots = 0, cummwindspeed = 0.0;
[Code] ....
In the code above, how exactly the scanf takes the inputs from the user and then stores them for me to access. So, I want my array to be 3 columns, for months , wind_speed, & minpress. The array has a undetermined amount of rows. I think if I figure out the first array, I can handle the second.
If I have 2 arrays, say array1 = {2, 2, 4, 5, 6} which has sorted array elements and array2 = {4, 2, 6, 2, 5} that has same elements as array1 but not in sorted condition. How can I compare that both arrays have same elements. I have written the following code which works in all conditions except when array1 has two same elements and array2 has all different elements.
counter=0;
for (i=0; i<5; i++) {
for (int j=0; j<5; j++)
if (array2[i] == array1[j]) {
counter++;
array1[j]=0;
[Code] ....
I have created a new array and have wrote a code which will decrease || increase the value of the array element. I been trying to figure out how to set the value limit. For Example:
int[] stock = new int[] { 10, 10, 10, 10 };
How to set a limit on the elements that they will never go below to the negative integers and over 10?
So I'm trying to make two arrays, then the third array that will include common elements of those two arrays. I did make a code for that, but the problem is I don't know how to include that the elements do not repeat.
For example, if there are two arrays,
Elements of the first one: 2, 3
Elements of the second one: 2, 3, 2
The third array is going to be: 2 2
While I want it to be only 2.
#include <iostream>
using namespace std;
int* intersection(int* n1, int d1, int* n2, int d2, int& d3) {
d3=0;
for (int i=0; i<d1; i++) {
[Code] ....
int result = 1;
for (int j=0;j<N;j++) {
bool found = false;
for (int i=0;i<N && !found;i++) {
if (a[j] == b[i]) found = true;
}
if (!found) return 0;
}
I need to create a code that compares two in arrays without sorting them. They have to be the same length and contain the same elements in any order.
every integer in a[] is also in b[]
every integer in b[] is also in a[]
all such common values appear exactly the same number of times in both a[] and b[]
EX: a = {1, 2, 3}, b = {2, 3, 4} return 0 a = {1, 2, 3}; b = {2, 3, 1} return 1 a = {1, 2, 2}; b = {2, 2, 1} return 1 a = {1, 2, 2}; b = {2, 1, 1} return 0 a = {1, 1, 2, 2, 2}; b = {2, 1, 2, 1, 2} return 1
This is all i have...
Supposing you have a 3 or more overlapping arrays (arrays having elements in common), and you wish to select 2 or more of the arrays with the maximum number of elements but less overlap as compared to the rest of the overlapping arrays.
Eg. A[4],B[6],C[5]. A+B contains 10 elements but say the overlapping element is 3, meaning it has 7 unique element.
Also B+C=11 elements , but supposing it has 5 overlaps, it would mean it has only 6 unique elements. A+B+C=15. Supposing the overlaps are 11 then it means the unique elements are 4. Ect. So per the example, the best array options with most unique element would be A+B .
I have a matrix that contains zero and nonzero elements. I want to do a function that return 3 arrays.
The first one is for nonzero elements the second array contains the corresponding row numbers of each nonzero element the third array contains the corresponding column numbers of each nonzero element.
I have a txt file that looks like this:
Student ID:97707; Grades: 87.73, 90.41, 91.74, 95.04, 99.13; Name:Davis, Artur
Student ID:23628; Grades: 58.09, 65.18, 68.62, 68.62, 98.05; Name:Davis, Susan
Student ID:49024; Grades: 18.37, 66.06, 68.07, 80.91, 96.47; Name:DeGette, Diana
-I need to read the id, grades and names;
-The id to a separate array
-The grades to a 2-d array
-And the names to a c style string.
Where do I start, im having trouble read the dummy to start
int main() {
char filename[15] = "ex.txt";
string names[MAX_NAMES];
double grades[MAX_ROWS][MAX_COLS];
int id[MAX_IDS];
int index = 0;
ifstream fin;
[Code] .....
I define "Comwords" as a string, but apparently it takes the members as chars, then I can't set strings in a structure equal to the chars.
I see to also be having unknown problems with the ComMAL array and loading it values into another element of the same structure.
How to correct this? I was thinking of casting char elements as strings, but could find no reference in my library book regarding how to do that (lots on casting int's a doubles...)
Code:
int _tmain(int argc, _TCHAR* argv[]) {
int comm = 10;
int targ = 5;
int death;
struct AI_WORDS
[Code]....
Using a for loop, construct two 100 element arrays, x and y, such that element i of x stores the value sin(2*pi*i/100)) and the corresponding element of y stores cos((2*pi*i/100)). Print the values stored in the elements of x and y as you calculate them.
I have attempted to solve it but I'm not sure why the value 0 is only being printed, maybe I haven't assigned sin(2i/100)) and cos((2i/100)) to the arrays properly?
Code:
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main () {
[Code] .....
I have the following map: myMap<string,vector<int>>. I now want to look through my map to see if a key exists and if it does, retrieve one of the int values from within that vector. What would be the best way to do this? Right now I have the following:
What would be the best way to look for a key and get one of the int values from its vector value? Right now I'm doing something like this:
[code]
map<string,vector<unsigned int>>::iterator it;
it = wordMap.find(someWord);
if(it == wordMap.end){
cout << "No matching entry";
} else{
// this is where I'd want to access the value (the vector) of the map
}
Is there a better way to do this?
I don't have in depth code or anything. I tried this but can't seem to wrap my head around it.
Code: //header.h
namespace test {
int arr[5];
[Code] ....
Also tried putting int arr[5] in a Test class within test.h.
I have 2 structs in another file, the main, and want to make an instance of the arr variable, in a separate header, for each.
How to i access setter from within a setter?
I know that getter methods can be access like
Code: getAccounts().getAccountNumber();
// for example but for setters how do i do it? this doesnt seem to work though
Code: setAccounts().setAccountNumber(accountNumber);
Here is the link for my program, I want to access the average value which is located in grade.c (calculate_grade) class through driver.c (main function) but I don't know how to make "average" visible
[URL] .....
I've been attempting to create a game with curses and I keep running into the problem of scope. I want to change or use variables of a different class in a different header file. But I don't know if I should use pointers, references or neither. Should I be programming in a manner that doesn't make it necessary to use variables outside of their class?
View 1 Replies View RelatedI'm currently trying to access a variable contained within a base object from another completely different object and I continually get error messages. I'll attempt to put up the important code since it's contained within fairly large classes. From the Base .cpp file. ObjectPosition:
void ObjectPosition::init(float x,float y, float speed, int boundx, int boundy, float hit, int lives, bool live) {
ObjectPosition::x = x;
ObjectPosition::y = y;
ObjectPosition::speed = speed;
ObjectPosition::boundx = boundx;
ObjectPosition::boundy = boundy;
ObjectPosition::hit = hit;
ObjectPosition::lives = lives;
ObjectPosition::live = live;
}
This is the initialization function for the BaseObject. All objects are inheriting these variables which are Protected within the ObjectPosition class.Then they are initialized within the Pig class thus wise:
void Pig::binit(float sx,float sy, ALLEGRO_BITMAP *simage) {
//Sets all ObjectPosition Variables
ObjectPosition::init(800,900,10,80,40,40,10,true);
smaxFrame = 4;
scurFrame = 0;
[code]...
I tried to initialize the boundx through the pig via pinitx but I get errors and I can't access through the pig to the object position to the boundx.
I have a Visual C++ solution file that contains 3 projects. i want to access the variables declared in a function in a project from a function in another project. Function declarations are in .h file and expansion in .cpp files. Can i use friend class or any other suitable method.
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