Here is the part of my code that I need to return two values. I am working on a roulette program and I need to return the choice and the number they are betting on. How can I use a pointer to achieve this?
Code:
int makeBet(char choice, int num){
printf("
What type of bet would you like to place? ");
printf("
Type n for number.
Type e for even/odd.
Type d for dozen.
[Code] ....
Here is what's up:
struct Square {int number, myClass* myclass};
int main() {
vector<myClass> classes;
myClass unrelated;
classes.push_back(unrelated);
Square newClass = {3, &classes.at(0)};
.
.
.
myClass is a class I have. Now, in the class, I have a function what_value and I need to get the classes.at(0) from the pointer to it in another function. But the problem is, how can I do it? I'm completely stumped, here's what I thought of:
newClass.*myclass.what_value();
And it I get an error from the compiler. Basically, how can I do this in another function with a pointer:
classes.at(0).what_value();
I wanted to return a string I can do
Code:
string parseFilename(string fileName){
return fileName.subtr(/*blah*/);
}
Can I also use pointers/references here though? When would you use a pointer and when just a return statement?
How to return as a pointer to a string?
View 5 Replies View RelatedI am trying to return a pointer from a method. Below is a sample of my code.
CSubnode * CTest::GetSubNode() {
return m_psubnode;//this is declared in CTest as CSunbnode * m_psubnode
}
//in another class
m_subnode = m_ptest->GetSubNode(); //m_subnode is declared as a pointer
Is this the correct why to return a pointer?
Write a function named cointoss that simulates the tossing of a coin.
When you call the function, it should generate a random number in the range of 1 through 2.
If the random number is 1, the function should display "heads".
If the random number is 2, the function should display "tails".
Demonstrate the function in a program that asks the user how many times the coin should be tossed, and then simulates tossing the coin that number of times.
Report the total number of heads and tails.
Ok here is the code
//assuming that all the directives have been included here
void ptrPointer(vector<string>* const p, int n);
int main() {
vector<string> inventory;
vector.push_back("sword");
vector.push_back("knife");
[Code] .....
Well...my question is how come the last statement or cout statement to be accurate won't work and display? Since we can do something like this below?
string text = "some text";
string *p = &text;
cout << p;
I passed the address of the vector to the function. And then display the address. It is a pretty common operation. But it just won't work. But then we do something simple similar to that of the vector. But it works.
You can return values from functions by ref, address or value you can also do this with parameters, so what is the difference, if you have full return of a passed parameter by ref or address why would you need to ever return the function as a whole?
For ex
Code: int nValue(int& y){
y++;
}
or int& nVlaue(int y){
return y;
}
I need understanding the logic behind this function. The function is supposed to "Return a pointer to the character at the index given" . For example, what exactly are we declaring at "(char * const c, int index)"? where does "index" come from or equal to in the body of the function?
Code:
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char * GetValueAtIndex(char * const c, int index)
{
int i = 0;
char *p = c;
while (i++ != index)
p++;
return p;
}
I've got the program for the most part except one part because it's basically wanting me to return 3 values from a single function and I'm unsure how to do this the way it wants me to. The rules:
Call the user-defined function to read in x in the series to be used for calculating the results. Pass a prompt for x as an input parameter, and return the validated x value to main.
After a valid x has been entered, call the same user defined function a second time, to read in y. Pass the prompt for y as an input parameter, and return the validated number of terms value to main.
After a valid y has been entered, call the same user-defined function a third time, to read in z. Pass the prompt for z as an input parameter, and return the validated z value to main.
While working on another issue I started memory cleaning and refactoring. While refactoring I decided to create an array Resize Array Reize and Null Count:
Spoiler
public int NullCount(string[,] Original) {
try {
int returnInt =0;
for(int x =0; x<= Original.GetUpperBound(0);x++) {
if (Original[x,0]==null )
{returnInt++;}
[code]......
/*
* symboltable.c
*/
#include "symboltable.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "include/utlist.h"
[Code] ....
question from chapter 11, qn 8 modern C programming by king
Write the following function: Code: int *find_largest(int a[], int n); When passed an array a of length n, the function will return a pointer to the array's largest element
Code:
#include <stdio.h>
int *find_largest(int a[], int n)
{
int i, x;
x = 0;
[Code].....
have traced the code line by line and it prints correctly up to line 31. However, when the program exits (line 35) , it goes to some other screen with very complex code and my output disappears.
Just to clarify: If I just run the code as is, there is no output. However, when I trace the code line by line, the output appears, but then disappears as the program exits My input was 1 2 3 4 5 6
in a function how do you return multiple values to the main function.
View 4 Replies View RelatedI am trying to understand RValue-references as return values of functions. First let's consider a simple function, that transforms a string into upper case letters.
const std::string
toUpper(std::string orig) {
std::transform(orig.begin(), orig.end(), orig.begin(), ::toupper);
return orig;
[Code] .....
It compiles, but I get the output 0 . Here I am wondering why the code above does not move the substr correctly while the code below does (prints out 1):
const std::string&&
no_sense(std::string abc) {
abc = abc.substr(1, 1);
return std::move(abc);
[Code] .....
In both cases abc is a temporary object inside of the function and gets deleted after the function is left. But why does the second version work and the first one does not?
cat.substr(1, 1)
And as my last question. Why doesn't
return std::move(abc.substr(1, 1));
work?
I'm trying to test if a character is a vowel. I made a separate function for the test, I'm not really sure how to get my return value to output whenever I call the function from main?
Also, I'm not good with while loops and can't figure out how to get it to continue asking whether or not the user wants to keep entering values.
#include <cstdlib>
#include <iostream>
using namespace std;
bool isVowel(bool);
int main(int argc, char *argv[]) {
char var1, cont;
[Code] ....
I'm trying to write a function that returns a pointer to a dynamically allocated array. Here's my code:
#include <iostream>
using namespace std;
void IndexArray(int, int);
int main(){
int *arr, n;
[Code] ....
When I try running the program, I get the error
"Unable to start program 'D:C++FilesdynamicArraySolReleasedynamicArray.exe'. The system cannot find the file specified."
I'm honestly not sure if the issue is my program, or something with C++. At the moment, I cannot debug any of my programs or else I get the same exact error. I basically need to release everything without debugging it. I last used C++ about a year ago and I'm finally back in school, and so trying to get back into it. I use Microsoft Visual C++ 2010.
Is there anyway we can return 2 values from a called function. Example
Code:
float xxxx(float a, float b, float c, float d)
{///
///
///
}
void xxx() {
int e,f,g,h;
////
////
xxx(e,f,g,h);
}
So if I want for example a+b and c+d, can i return those 2 answer? I don't think its possible since I am new into C programming.
I have a function that I want to exit gracefully when an "error" occurs in an input file. My function declaration is:
Code: BSTnode *buildTree(FILE *fp)
The few lines that are causing the problems are:
Code: if(regcomp(®ex, to_find, REG_EXTENDED | REG_NEWLINE) != 0) {
fprintf(stderr, "Failed to compile regex '%s'
", to_find);
return EXIT_FAILURE;
}
I know that if I just use "return" by itself the warning goes away but fails to exit when the error occurs. I also believe this may not be the correct use of stderr. But I need the program to exit when an error has occurred.
I am making a function that will return a pointer to a long long variable. For example, I have the next variable prototype: Code: long long funcName(long long x, int s); I want to change the return value, and the first parameter to pointers to long long.
View 4 Replies View Relatedi need to return a struct pointer dynamically allocated inside a function call void function() which is done using 'out parameters' in following code
struct my_struct {
int x;
} void my_function( my_struct** result ) {
my_struct* x = new my_struct{ 10 };
//...
*result = x;
}
Now i have a doubt, so if i want to print the return value from struct pointer, should i need to print it in the void function() or in the caller the function...
// I believe my loop for the functions work but the values are not returning !
// Acoustic data
#include <iostream>
#include <fstream>
using namespace std;
double low( double []);
double high( double []);
void readArrayr( double [], double , double);
[Code] .....
I am writing a class Player which has several char arrays as private fields. I am trying to write a method which returns an array as a pointer, but doesn't alter the array in any way, thus the const.
Here is a snippet:
Code: class Player
{
private:
char state[MAX_STATE_CHAR + ONE_VALUE];
int rating;
char last[MAX_NAME_CHAR + ONE_VALUE];
char first[MAX_NAME_CHAR + ONE_VALUE];
int groupNumber = NEG_ONE;
public:
char * GetFirst() const
{
return first;
}
Visual studio is saying that the return type doesn't match.
The code below is supposed to fill, show, and revalue property. The fill function is supposed to return a pointer that creates a range of property values. The show function is supposed to show the property values entered and the revalued property values. I think part of the problem is the returned pointer from the fill function. Once that is cleared up, I think I will find more problems.
Code:
#include <iostream>
const int Max = 5;
// function prototypes
double fill_array(double ar[], int limit);
void show_array(double * begin, double * end);
[Code] .....
I have an application that reads a process and return values from it. The problem it works fine with small processes but i have some processes that are about 1GB or even 2GB and when i try to read such big processes the application crashes. I'm trying to find a way to read the process memory in chunks of maximum 10 MB. The read code looks like:
Code:
HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, entry.th32ProcessID);
unsigned char *p = NULL;
MEMORY_BASIC_INFORMATION info;
for (p = NULL; VirtualQueryEx(hProcess, p, &info, sizeof(info)) == sizeof(info); p += info.RegionSize)
[Code] ....
This reads the info.regionsize which can be as large as 100 MB. Is there any way to read it in chunks ?
I am using pointer to display values of an array but its output is not correct example 23424,0, -323423 etc... whats the problem with my code:
Code:
#include<stdio.h>
#include<conio.h>
int main() {
clrscr();
int arr[10][10],rows,cols;
int* ptr;
[Code] ....