I have a problem with pointer array, i passed a 2d array to a function but then i dont know how to make operations on it !!!
#include <iostream>
using namespace std;
int fun_name (int * arr) {
for (int i = 0;i< ??? ;i++) // how to compare while i don't know the size of array!!
[Code] ....
Say I have a class that requires dynamic allocation to implement a few of the operators. Take "+" for example; I need to create a new object to hold the sum of the two parameters whose size is not known at compile time.
I'm pretty sure the standard way to indicate a failure inside the overloading function would be to throw an exception. However I am currently involved in an embedded(ish) project where the spec. says no exceptions are to be used.
I think I have 2 options:
1. Return an "invalid" object (with a flag indicating an error has occurred) and check for this after each operation.
a = b + c
if (a.err)
// handle error
or
2. To forsake operator overloading entirely and think up a new way of doing things where all functions that involve dynamic allocation can return error codes. but this seems rather terrible too as I may end up with something like:
objA a
if (add(&a, b, c) == -1) // assuming b and c are initialized before this snippet starts
// handle error
Is there a number 3 that I haven't thought of? It seems that not allowing exceptions is fairly common even in the non-embedded world [URL] so how is this normally done? or is operator overloading usually avoided when exceptions are not allowed?
Ive recently got into function pointers, i find that they can be quite handy for making your program very 'dynamic'.
However, the syntax is very confusing for what i want to do
This is what i want to do
I want to hold function pointers inside an array, but this array is dynamically allocated ( malloc, realloc, etc )
This is the current syntax ive come up with, but i dont think it is correct
void ( **drawFunc ) ( void*, SDL_Surface* );
I am new to C++ and am trying to modify an array inside of a function.
It is of my understanding that you cannot return an array from a function?
Would writing it to a data file and then retrieving it be a solution to this problem?
im tasked with creating a linear search script using functions on a 10 element array. the elements are to be supplied by the user as is the search target.
I understand how to create the array and gather that information from the user as well as howto set a variable for "target", this is what im calling it. Those two parts are simple enough.
I am not fully understanding the calling of an array in a function as a pointer. i semi understand the use of a pointer and howto call a normal pointer in a function. i also understand that an array is nothing more then a "special" pointer with a set of consecutive address blocks for the size of the array.
My first user defined function is simple enough
Code:
ReadArray(int A[], int size){
int i;
printf("Please enter %d integer numbers separated by spaces:
", size);
for (i = 0; i < size; i++)
scanf("%d", &A[i]);
}
Sso nothing out of the ordinary there. that should be a standard for loop and use of scanf, sadly prof has not covered ssanf or any of the other options so i am stuck using scanf for now. maybe someday down the line in a other program or after this course ill get the chance to learn about better options for gathering data from the user.
I am confused as to my next function:
Code:
void SearchArray(int A[], int target, int size);
I've not written any code here yet as im not sure if i should call the A[], or *A for the first type of the function?
If i call *A do i then use something like this for my search:
Code:
for (*A = 0; *A < size; *A++)
if (*A < target) or use A[] insteadA?
Code:
for (i = 0; i < size; i++)
if (A[i] = target)
i want to use a class to print data stored as vector or array with different data types. i also want the print function two take more than one vector or array or combination of both so that they can be written to file as two columns. so i wrote the following class:
right now it has only one member function for printing two vectors. later i'll add additional functions as required.
note: there has to be template functions inside the class
i also want the object to be global so that i need not pass it as an argument to other calling functions
class printdata
{
public:
template<typename T1,typename T2>
void SaveData( vector<T1> &data1,vector<T2> &data2, std::string var)
{
[Code]....
then i want to call this template function in another ordinary function written in a seperate cpp file
these function declarations are put in a header file. so i need know whether i should put the declaration of the template function in the header to use the function in different functions
i want to use a class to print data stored as vector or array with different data types.
i also want the print function two take more than one vector or array or combination of both so that they can be written to file as two columns.so i wrote the following class:
right now it has only one member function for printing two vectors. later i'll add additional functions as required.
note: there has to be template functions inside the class / i also want the object to be global so that i need not pass it as an argument to other calling functions
class printdata {
public:
template<typename T1,typename T2>
void SaveData( vector<T1> &data1,vector<T2> &data2, std::string var){
std::ofstream myfile;
std::string filename;
[code].....
then i want to call this template function in another ordinary function written in a seperate cpp file these function declarations are put in a header file. so i need know whether i should put the declaration of the template function in the header to use the function in different functions.
So, I finally got translations for all the strings I'm using. However, depending on the language, the strings can exceed the space of the user controls, tabs, buttons, etc.. So in some parts, the words are either completely cut off or the word itself is cut off midway and finishes on another line.
I am wondering what is generally done about languages that use really long strings?
Should I reduce the font size or use multiline? Are there any best practices for this scenario?
This is for a WPF project.
I 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;
};
There are many questions on the web on how to fix a specific signed/unsigned mismatch, and the solution is usually just making one variable unsigned.
I have a grid (x,y) which should be unsigned, since you can't have a (-5,-3) sized grid. However, I have a Direction object which should be signed, since I can have a (-1, -1) direction. The problem is when I do something like Location_x + Direction_x > grid_x which throws the signed/unsigned mismatch warning.
I have a problem in dealing with dynamic arrays. I have initialized the objects and now i want to print them.
Code: // main
char* namesList[] = {"Brad Shaw","Aimen Adams","Sal Dimitry","Cristi Anreaz","Poala James"};
int idList[]={232,444,135,52,134};
Team t1( namesList,idList,5,"waqas");
t1.Print_team(); My class Team looks something like this:
[Code] ....
The print function does not work. I have to implement the print function without taking any parameters.. How should i do that ?
My assignment is to create a program to print a deck of 52 cards, shuffle it, deal 2 hands of 5 cards, then print the deck after dealing the 2 hands with the cards that were dealt removed. this is my code so far...
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define DECK_SIZE 52
void init_deck( int deck[] , int size ) ;
void shuffle_deck( int deck[] , int size ) ;
[Code] ....
I am having trouble dealing 2 random hands and how to print the deck with the cards removed.
I keep on getting error message while trying to pass a function inside a for_each loop.. I have a vector and i used for_each loop to go through the rows in that vector, Now I need a function to do something
Example this is what I am trying to achieve
for_each (label.begin(), label.end(), addToTemporaryVector());
void DataPartitioning::addToTemporaryVector(){
cout<<"sucess";
}
But I get an error message saying: error: invalid use of void expression
I've written a simple program, which asks the user to respond to a YES or NO question using the character Y/y for YES and the character N/n for NO. The foundation of this program is based around several IF statements implemented to aid in finding the ASCII value of the character entered before invoking the corresponding cout statement that informs the user which character they entered. My Question: How should a program be written to deal with ignoring case sensitivity in regards to the users' input?
Here is my amateurish attempt,
Code:
#include <iostream>
using namespace std;
int main()
[Code] .....
The following are IF statements written for the program to determine whether the user answered YES or NO. The program then performs the cout statement that contains the corresponding character to the ASCII value found.
*/
if(user_input == 121 || user_input == 89)
{
if(user_input == 121)
{
cout << "
[code]......
How would I generate nodes inside a function for example I have a head node
Node * head = new Node;
Now I want to generate nodes for as long as the for loop is running
void CreateList(Node * h) {
for(int i = 0; i < 5; i++) {
Node * n1 = new Node;
head -> next = n1;
} }
Something like this but it should keep adding nodes to the list and change the head each time so how would I do this...
i usually use this method for accesing functions in executables, the code is executed from a DLL (always works, except when the function are inside of a class, even tho is public):
.h:
typedef int (*pgObjViewportClose) (OBJECTSTRUCT* gObj);
extern pgObjViewportClose gObjViewportClose;
.cpp
pgObjViewportClose gObjViewportClose = (pgObjViewportClose) 0x04F1940;
That works, but i can't get it to work if the accesing function is inside of a class, i get Unhandled Exception while trying to access a function inside a class, is there a way to do it?.
I want to have a function pointer inside a typedef struct but I get a segmentation fault when I run my code. Here's my code:
#include <stdio.h>
typedef struct Foo {
void (*bar)(int);
} Foo;
void func(int x) {
printf("display: %d
[Code] ....
Is this standard-compliant code?
int f() {
class C {
public:
int mf() const {return 1;}
};
C c;
return c.mf();
}
In the following code:
#include <iostream> // For stream I/O
using namespace std;
int function(int a) {
return a;
}
int main() {
function(int b);
}
Why is creating a variable inside the function argument list not allowed. Any reason other then for the language syntax or just for the language syntax?
Say you had:
class Foo{
public:
//...
void funky();
[Code] .....
Would each instance of Foo create a new counter variable, or would it remain the same for all of them, i.e. baz.funky() would always use the same counter variable? What if the class was a template?
This is a program I developed in which we had to define a class named BOOK with the data members and member functions as shown in the program..We have to:
(i) Make the user enter the values in the array BOOK.
(ii) Display the details that the user entered.
(iii) Search for a book from the array upon its Bno and display its details.
(iv) Search for a book from the array upon its Bname and display its details.
PROGRAM:
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<string.h>
class BOOK {
private:
int Bno;
char Bname[20];
[Code] .....
But while running it the compiler gives the errors as:
Line 43 to 48: Illegal character '' (0x5c)
Line 69: Undefined symbol 'Display'
Line 88: 'BOOK::Bno' is not accessible.
Line 89:'BOOK::Bname' is not accessible.
Line 90:'BOOK::Author' is not accesible.
Line 91:'BOOK::Price' is not accesible.
Line 108:'BOOK::Bno' is not accessible.
Line 109:'BOOK::Bname' is not accessible.
Line 110:'BOOK::Author' is not accesible.
Line 111:'BOOK::Price' is not accesible.
from 43 to 48..the line feed was also used at many other places but there it was not given as an error so why here?
Line 69: I defined the Display() function outside the class since it contained control structures, so what's the error then?
About the lines the rest of the error( the "not accessible" ones) I know these data members are not accessible because they are in private visibility mode. But then how to make them accessible? (Without putting them in public because it was a part of the question to create the data members in private).
I've written an Array class to create 1d,2d and 3d array and it works fine for every test : example of the constructor of the array class for 2d case:
Array::Array( int xSize, int ySize ) {
xSize_ = xSize;
ySize_ = ySize;
zSize_ = 1;
vec.resize(xSize*ySize);
}
It works fine , but when i need to use this constructor inside of other constructor, i get the "no matching function error" ,
part of my code:
class StaggeredGrid {
public:
StaggeredGrid ( int xSize1, int ySize1, real dx, real dy ) : p_ (2,2) {}
[Code] .....
So, I have this code:
...
MakeTexture((char*)ilGetData(), ilGetInteger(IL_IMAGE_WIDTH), ilGetInteger(IL_IMAGE_HEIGHT));
...
And it compiles fine and, supposedly, works fine too, but when I try to put a break point inside the MakeTexture fuction gdb just goes crazy, it freezes and starts alocating memory until it reaches like 30+ mbs, and after that codeblocks freezes and I have to terminate the gdb process to return everything back to normal.
Now, another weird thing is that this only happens if I pass (char*)ilGetData(), if I pass something like NULL to the function, this doesn't happen.
Oh, also, the MakeTexture function is this:
int MakeTexture(char *pxData, unsigned w, unsigned h)
{
return 0;
}
Alright, so I have a code that's not giving me errors, but it doesn't seem to retain what I put into an array. Not sure If I'm missing something...
Code:
#include <stdio.h>
int main (void)
{
const char *pointer;
const char alphabet[] = "ABCDEFG";
pointer = &alphabet[5];
printf("pointing to %c of the alphabet
", pointer);
return 0;
}
Trying to get my pointer to return the letter in the [5] spot or "F". Not receiving any errors when compiling, but I seem to get different answers every time I run it.
class Hallway {
private:
//---------------------------------------------------------------
// DO_04: Declare a Light array of size MAX_LIGHTS
// Hint: look through the methods below to find the name to use
// for the array
//---------------------------------------------------------------
int numLights;
int lights[MAX_LIGHTS];
[Code] .....
I keep getting the error " this.lights[i] is not a struct or class and so you cannot use '.' " on line 34.
How am I supposed to define my lights[] array? I can't modify anything except directly after each comment block.
I have one array with size of 5 and passing this array to one method. I want to get size of the array inside method. If i get size of array inside method, i'm getting only "1",but not "5".
int v[5];
v[0]=1;
v[1]=2;
v[2]=3;
v[3]=4;
v[4]=5;
cout<<sizeof(v)/sizeof(&v[0])<<endl; // here i'm getting size as 5
CreateArray(v);
void CreateArray(int val[])
{
cout<<sizeof(val)/sizeof(&val[0])<<endl; // here i'm getting size as 1
}
Is there any way to get size inside method ?
