C :: Passing Array As A Parameter To Function
Oct 6, 2014How come when we pass an array as a parameter to a function, the entire array is copied and is available to function?
View 1 RepliesHow come when we pass an array as a parameter to a function, the entire array is copied and is available to function?
View 1 RepliesWrite a program that inputs 10 integers from the console into an array, and removes the duplicate array elements and prints the array. By removing, I mean that you should make it appear as if the elements hadn't been there. You may assume that all the integers are between 0 and 100, Write at least 1 function in addition to the main function, and pass an array into that function as a parameter. e.g.
Please enter your 10 numbers: 1 2 3 4 5 6 7 8 9 10 The array contains: 1 2 3 4 5 6 7 8 9 10
Please enter your 10 numbers: 1 1 3 3 3 6 7 8 9 9 The array contains: 1 3 6 7 8 9
Please enter your 10 numbers: 1 1 1 1 1 1 1 1 1 1 The array contains: 1
The bolded area is where I'm having trouble. How I can go about doing this, passing an array into the function as a parameter?
Here is my code:
#include "stdafx.h"
#include <iostream>
using namespace std;
int main () {
const int MAX = 10;
int a[MAX] = {0};
int i;
[Code]...
gcc v.8.3 -std=gnu++11
[URL]
I'm trying to pass a function as a parameter and failing. It seems simple, until I get the error messages.
Here is the code:
class MinimalSolver {
typedef double (*func)(double sum, double char);
void driver();
[Code]....
Pseudocode:
template<typename T /*, some parameter for member_function */>
class Foo {
public:
void someFunction() {
T t;
t.member_fuction(...);
} }
I'm trying to make the call to T::member_function a templated value because member_function might vary by name in my scenario. Since std::mem_fn isn't a 'type', i can't do something like Foo<std::string, std::mem_fn(&std::string::clear)> foo;
I also want to take into account that member_function might have more than one parameter. That is, the first parameter will always be something known but there might be other defaulted parameters.
The only thing I can think of is to make a proxy structure, something like this:
template<typename T, T> struct proxy;
template<typename T, typename R, typename... Args, R (T::*member_function)(Args...)>
struct proxy<R (T::*)(Args...), member_function> {
R operator()(T &obj, Args.. args) {
return (obj.*member_function)(std::forward<Args>(args)...);
} }
Which would then allow me to do (for example) this:
Foo<std::string, proxy<void(std::string::*)(), &std::string::clear> >
when Foo is implemented like this:
template<typename T, typename member_function>
class Foo {
public:
void someFunction() {
T t;
member_function()(t);
} };
That implementation works for me.
I created the following code to pass the the variable 'inputVoltage' by reference to the function 'input'. It certainly works when I run the program, but I dont think it is a standard way of doing it, i.e. the use of '*' and '&' is not according to convention ? Or perhaps the way did it is acceptable ?
int input (double *inputVoltage);
int main ( {
double inputVoltage;
input(&inputVoltage);
[Code]....
I have a class and I would like to be able to pass an extra parameter to the function that is executed.
BigInt operator / (BigInt N,BigInt D) {
...
}
is what I have now. but I would like to do something like this. so the default value for a is 10. and if the user does something like N/D (12) Then the value of a is 12.
BigInt operator / (BigInt N,BigInt D, int a=10) {
...
}
I have a class matrixType that has some overloaded operators (+, -, *, and <<). With a view to having clearly-delineated, perfectly-formatted, four-sided matrices, as shown below:
A = 1 2 3
4 5 6
7 8 9
or
A + B = 1 2 3
4 5 6
7 8 9
and NOT this jagged ones shown below:
A = 1 2 3
4 5 6
7 8 9
or
A + B = 1 2 3
4 5 6
7 8 9
,
I want a scheme in which the string literals (A, A+B, etc.) could be passed as parameters to the overloaded stream insertion (<<) operator function so that I could use the string’s length to determine how much offset from the display screen’s left to apply to each matrix’s row (by using the setw() function). However, I do know that the << operator is a binary operator, meaning the function cannot take more than two parameters: that is what compounds my problem!
Basically I'm trying to pass an object as a reference to the template function, rather than a copy as it's seeing. I'm needing to do this without editing Obj::Call to accommodate a reference as its first parameter, as it'd break other calls.
You'll notice in the following code the object will be destroyed upon passing, while the object defined is still in-scope due to the infinite end loop.
#include <iostream>
#include <string>
using namespace std;
class Obj {
public:
string name;
Obj(string name): name(name) {cout << "create " << this << endl;}
[code]....
In the past I tried ref(), which appeared to stop this happening, however it created a blank copy of the object instead.
I have been working on this all day, and its due in like an hour and a half. I have done everything the program wants except the last part. Here is the assignment:
Write a program that inputs 10 integers from the console into an array, and removes the duplicate array elements and prints the array. You may assume that all the integers are between 0 and 100, Write at least 1 function in addition to the main function, and pass an array into that function as a parameter. e.g.
Please enter your 10 numbers: 1 2 3 4 5 6 7 8 9 10
The array contains: 1 2 3 4 5 6 7 8 9 10
Please enter your 10 numbers: 1 1 3 3 3 6 7 8 9 9
The array contains: 1 3 6 7 8 9
Please enter your 10 numbers: 1 1 1 1 1 1 1 1 1 1
The array contains: 1
The bolded part is what I cant get to work. I have tried this and it keeps telling me I have not identified the items when I have.
Here is my code:
#include "stdafx.h"
#include <iostream>
using namespace std;
[Code]....
My errors are at the end of the program in two function calls within the definition of the InsertByValue function. g++ does not seem to recognize NumArray as a valid parameter.
#include <iostream>
#include <assert.h>
using namespace std;
const int CAPACITY = 20;
/* Displays the content of an int array, both the array and the size of array will be passed as parameters to the function
@param array: gives the array to be displayed
@param array_size: gives the number of elements in the array */
void DisplayArray (int array[], int array_size);
[Code] ....
The printArray function should take in the dynamically created array and the size of the array as parameters. It should print out the contents of the array.
#include <iostream>
#include <string>
using namespace std;
[Code].....
My problem is that how to write the code to print the array using pointers. I've been stuck for awhile trying to figure it out.
i need to write a function with an array parameter and an int parameter.
that array has to be filled with first 10 prime numbers that are exact or higher than the int parameter...and then i need an average value of those 10 prime numbers...
The problem is im not really sure how i should do the part to fill the array with prime numbers that are higher than that int??
Code:
int avgprimearray (int higharray[], int somenumber){
}
Code:
#include <stdio.h>
void ASCII_to_EBCDIC( size_t, unsigned char *);
void EBCDIC_to_ASCII( size_t, unsigned char *);
void to_ASCII(unsigned char *);
void to_EBCDIC(unsigned char *);
/* conversion tables */
static unsigned char
[Code] ....
The above snippet is for a buffer/string, where as i want to pass file name as a parameter and want function to process the file line by line?
#include <cstdlib>
#include <iostream>
struct tax_node {
char form; // tax form letter
int version; // tax form number
[Code] ....
I cannot seem to get why function print_contents will not work. The couts at the end of the program is just to test that it printed correctly. But, if I need it to print the contents such when print_contents(ptr2) is called. I think it should be tax_ptr in the parameter list but I am not quite sure.
I want to create events and then, functions which are subscribed to the event can access information about the event. For example, in Class 2 below, I want it to be able to access things such as touch.position, etc. of class 1.
Class 1:
public delegate void TouchEventHandler (EventArgs e);
public event TouchEventHandler TouchBegan;
public Vector2 touchPosition;
void Update () {
if (Input.touchCount > 0) {
[Code] ...
Class 2:
void OnTouchBegan (EventArgs e) {
Debug.Log ("Ran");
}
I have this code:
const BYTE original[2][4] = {
{0x00, 0x00, 0x00, 0x00},
{0xFF, 0xFF, 0xFF, 0xFF}
};
void function(const BYTE** values){
[Code] ....
You might notice that the above code doesn't compile, this is the error:
cannot convert parameter 2 from 'BYTE [2][4]' to 'BYTE *'
1>
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
Even after some search I couldn't really find an answer to my problem, how do I pass the const BYTE array which I declared above in the function as a parameter (or what structure do I need to set for the function as a parameter)?
I've been playing around with this piece of code:
#include <iostream>
#include <string>
#include <algorithm>
template <void(*funky)(const std::string&)>
void callback()
{funky("Hello World!");}
[Code] ....
But when I try to build it, I get this error on line 24:could not convert template argument 'lambda' to 'void (*)(const string&) {aka void (*)(const std::basic_string<char>&)}'|
I thought the lambda expression I wrote would decay to a function pointer matching the template parameter. I can guess that the constexpr qualifier might have changed the type, but without it my compiler complains that lambda needs to be declared as constexpr...
So is there a way to pass lambda expressions as template parameters?
Without having to use std::function
In my project, GreedyKnap::calKnap(int nItem, int nCapacity, float fWeights, float fProfits);
This function include two array member pass as parameter. how can i do this?
Here is my issue: I am making a simple audioplayer in Xamarin.android but i want every time i change the track to make a crossfade effect. So im using 2 mediaplayers at the same time for the fade. The problem is that im defining one time the players and i pass the player as a parameter like this:
public MediaPlayer player = null;
public MediaPlayer player2 = null;
....
If i have to fadeout the player and start the next one im doing it like this:
if (player != null){
if (player.IsPlaying) {
cts = new CancellationTokenSource();
token = cts.Token;
FadeOut (player, 2000 ,token);
[Code] .....
So my problmem is that player and player2 remain always null. Why? i guess c# creates a copy of player and player2 and use this one. How i can pass a mediaplayer as parameter and always use only player and player2?
Does putting a ref when passing a struct to a parameter work? Say i have this code
struct struct1 {
public int i;
public void show() {
Console.WriteLine(i);
[Code] ....
The output doesn't change. The result is
0
100
500
0
I want to use one median function "selectfunction" to choose one of the 2 other functions at random to pass my 2-dim array to the selected function. There is a problem in the median function
#include <iostream>
#define random(x)(rand()%x) // for random number between numbers of 0 and 1
using namespace std;
void proc1 (int iArray[][2]);
void proc2 (int iArray[][2]);
void selectfunction(int iArray[][2]);
int A[4][2] = {{1, 2} , {3, 4} , { 5, 7} , {8, 1} };
[Code]...
I've was trying out a function template to automatically get the type of a lambda, but it seems that it won't compile
I've tried two different ways:
1.
template<class HASHER>
auto make_unordered_map(size_t bucketCount, HASHER const && hf)
-> unordered_map<string const, HASHER>&& {
return unordered_map<string const, int, HASHER>(bucketCount, hf);
} auto x = make_unordered_map(1, [](string const& key)->size_t { return key[0]; });
2.
template<class HASHER>
auto make_unordered_map(size_t bucketCount, HASHER const && hf2)
-> unordered_map<string const, int, decltype(hf2)> {
return unordered_map<string const, int, decltype(hf2)>(bucketCount, hf2);
} auto x = make_unordered_map(1, [](string const& key)->size_t { return key[0]; });
The test code are located here:
1. [URL] ....
2. [URL] ....
They are both based on the code that is stated to work in those examples. I.e.:
auto hf = [](string const& key)->size_t { return key[0]; };
unordered_map<string const, int, decltype(hf)> m (1, hf);
I wanted to print the values of a array from a function by passing the array as well as the number of elements to be read. For a single dimensional array, this is how i have written it. It's pretty straight forward. I want to read 5 elements from the 5th element in the array.
Code:
#include<stdio.h>
void display(int array[],int size) {
int i;
[Code]....
With this code I want to print the five elements from the element present in [0][4].
But shows an error that
Code:
D:BennetCodeblocks CLearning CSingleDimentionalArray.c||In function 'main':|
D:BennetCodeblocks CLearning CSingleDimentionalArray.c|18|warning: passing argument 1 of 'display' from incompatible pointer type [enabled by default]|
D:BennetCodeblocks CLearning CSingleDimentionalArray.c|2|note: expected 'int (*)[10]' but argument is of type 'int *'|
||=== Build finished: 0 error(s), 1 warning(s) (0 minute(s), 0 second(s)) ===|
I know when you pass a array as an argument it gets decomposed into a pointer, but with a multi-dimensional array this is not the case. how this works for mult- dimensional array's?
I'm wondering if it is possible to pass a 2d array to a function where the size of the array is not known at runtime.
I've tried
function ( array[][6] ) ;
But the size of the array has to be constant so it cannot be declared later.
I've tried using a template but you still have to declare the size of the array at runtime. Is this even possible at all?
The only other way I can think of is using a dynamic 2d array but how to create one and manipulate it.
I want to pass array to function, to fill array with new values and then to print the array in the main. But I have problem because it prints me just array of zeros. Maybe the concept is wrong, I'm new with passing arrays to function.
function:
Code:
void printSum(int *return_array) {
int return_array[3];
int i;
for(i = 0; i < 3 ; i++){
return_array[i] = 5;
Code:
void printSum(int *return_array);
int main {
int m_return_array[3];
int i,j;
for(i= 0 ; i < 3 ; i++){
m_return_array[i] = 0;
} printfSum(start,m_return_array);
[Code]...
I need to pass a 2D array to a function. I want to know, where I may have made a mistake. This is the piece of code that I found on the web, and I am using it to allocate my 2D array.
Code:
signed char allocate2D( int** arr2D, int rows, int cols )
{
int i;
arr2D = malloc( rows*sizeof( int* ) );
if( !arr2D )
return -1;
[Code]....
My main function passes the 2D array to the function
Code: signed char read_root_message_file( int **Root_Messages, int *num ) This is how I pass the array in the main function to the above function:
Code:
int main( int argc, char *argv[] )
{
int **Root_Messages;
...
...
Root_Messages = NULL;
read_root_message_file( Root_Messages, &num_root_msg );
[Code]....