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 this code:
#include <iostream>
#include <vector>
#include <map>
#include <string>
using namespace std;
[Code]...
and it does not compile.
The error is:
test.cpp: In function ‘int main()’:
test.cpp:20:30: error: no matching function for call to ‘func1(std::vector<int>&)’
test.cpp:20:30: note: candidate is:
test.cpp:8:45: note: template<class T, class U> std::map<T, T> func1(U)
test.cpp:8:45: note: template argument deduction/substitution failed:
test.cpp:20:30: note: couldn't deduce template parameter ‘T’
I always have confusions while using pointers with functions both as arguments and as return type.
View 1 Replies View RelatedThis code snippet just won't compile in a conforming compiler:
Code:
template<> struct series<0.0, 0, 0>
Because of the floating point template parameter.... If this "specialization" is useful, how come MS would have discarded it?
I'm trying to pass 2 arrays into a void funtion, and return values to one function.
this is the the program I'm working with, after I'm done I have to split it into 3 files, a header, a main, and a separate cpp file for the functions to live in.
#include <iostream>
using namespace std;
void processArrary(int numberCount[], int Numbers[], int intnumberSize, int numberCountSize);
int main() {
int Scores[26] = {76, 89, 150, 135, 200, 76, 12, 100, 150, 28, 178, 189, 167, 200, 175, 150, 87, 99, 129, 149, 176, 200, 87, 35, 157, 189};
int numberCount[8] = { 0 };
[code]...
The goal of this program is to separate and count the groups of numbers then output the amount of numbers in each group. Near as I can tell, everthing should work, but I'm getting all zeros to be displayed in each group.
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?
The function is supposed to return value from the file in my main, but I am getting empty value. I am trying to get better with pointer. Right now just teaching myself.
right now the only way for this code to show value is when in put the putchar(*ps) inside my readfile function. I would like to readfile to return value and print in the main function.
Code:
#include <stdio.h>
char *readfile(char filename[]);
int main(int argc, char *argv[] ) {
[Code].....
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'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.
in a function how do you return multiple values to the main function.
View 4 Replies View RelatedSuppose if i write a test program like
Code:
void function1(unsigned int var1);
int main(void) {
function1(-3);
}
void function1(unsigned int var1) {
printf("%d", var1);
}
The output is -3. how it happens the argument is unsigned but iam passing signed but still prints the signed value. My bigger question is how the arguments are handled if the passing parameters are different types compared to declaration.
// 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] .....
Write a function named maxValue that has three integer parameters. The function should compare the three values and return the highest value.
View 10 Replies View Related[URL] ....
#include <iostream>
#include <vector>
void f(std::vector<int> const &v, std::vector<int>::const_iterator it = v.end()) {
} int main() {
f({}); }
prog.cpp:4:73: error: local variable ‘v’ may not appear in this context
void f(std::vector<int> const &v, std::vector<int>::const_iterator it = v.end())
Why is this not allowed? (I mean, what is the reasoning for defining the standard this way?)
In C++14/C++17 we will have a unified way to represent end iterators without an instance of the container, but currently I just have to hope my implementation accepts a default-constructed iterator as an end iterator.
I'm fairly new to C++ and programming in general and I'm trying to get a program to check the parameters of a binary string before converting that string to dec values. I have the user input 'num' line 39 - 42, but I want to reuse that same value in the 'void bin_to_dec()' function. Is there anyway I can use the same variable between void functions?
13 #include <bitset>
14 #include <sstream>
15 using namespace std;
16
17 void dec_to_bin(){
18 string mess;
[Code] ....
Ok so I am working on a game and I'm in the process of developing my Player class. Anyways, what I have is a keyboard function that is called in my main function to make a shape move.
void myKeyboardFunction(unsigned char key, int x, int y) {
switch ( key ) {
[Code].....
But when I try to call it, trying to copy my previous method,
glutKeyboardFunc(Player1.playerControls);
I get an error
error C3867: 'Player::playerControls': function call missing argument list; use '&Player::playerControls' to create a pointer to member
I get an error saying it can't convert parameters. I would just like to understand why the arguments become a problem when I make the function a member of my class, when the first method I used is so easy.
I'm writing some functions pertaining to binary trees. I've used recursion once before while learning quicksort but am still quite new and unfamiliar with it. And this is my first time touching a binary tree. So my question: In my addnode function, will the return root statement at the end ever return a value other than the value passed to the function?
Code:
#include <stdlib.h>
struct tnode
{
int data;
struct tnode * left;
struct tnode * right;
}
[code]....
Write a constructor that initializes a new inventory object with the values passed as arguments, but which also includes a reasonable default value for each parameter.
#include "stdafx.h"
#include <iostream.h>
#include <stdio.h>
#include <string.h>
class inventory {
[Code] ....
I am not trying to get my homewotk done, just to understand my errors. It complies without problem. But doesn't run.
Which is more efficient in functions? Returning values or using pointers to redefine variables passed as arguments?
I mean either using:
void ptr_Func(int *x)
{
*x = *x+1
}
or
int ptr_Func(int x)
{
return x + 1;
}
In terms of speed, memory use etc.I want to know general efficiency, I know it will obviously vary with different uses and circumstances.
I am working on this project where I need a function to be called every second. At this time, I am thinking that I have to create a thread but I am clueless on how it will get called every second.
View 5 Replies View RelatedI am new to C and trying to reverse a string but the function is not getting called.. the console says :
Enter a stringabhi
bash: line 1: 229 Segmentation fault (core dumped) ./program
Code:
#include<stdio.h>
#include<math.h>
#include<string.h>
char* reverseString(char input[]);
void main()
[Code] ....
Here are the classes:
BaseClass.h
Code:
class BaseClass {
public:
BaseClass();
virtual ~BaseClass();
virtual void printStuff() const;
[Code] ....
When I call printStuff, the DerivedClass's function gets called. Now, if I remove the const part from the DerivedClass's printStuff function, we call the BaseClass's printStuff function.
There is already a thread with exactly the same problem I have, but the answer to solve the problem isn't stated at the end. Problem with callback as classmember.
View 4 Replies View RelatedAs I am taking my first steps in C, I study K&R (I guess most of you did the same, right?)
In the introductory chapter about functions (1.7) there is an example showing how to create a function that is then called to calculate powers (b**n). I simplified it to calculate only one given power, 2**5:
Code:
#include <stdio.h>
int power(int m, int n);
main() {
printf("%d", power(2,5));
[Code]....
It will then be called to make the calculation in the above string.
First things first: we already know how to use while(getchar!=EOF) to count characters (K&R chapter 1.5.2) but what if -instead- the input is a specific string? How to "read" it and how to tell my program that the string is finished? And most important: "reading" will be done in the function or in the rest of the body?
So on lines 36 - 39 (The commented out functions) is where I'm sure is causing this error because once I don't comment them out pretty much everywhere Flink or Rlink is used or defined I get this error.
#ifndef nodes_Nodes_h
#define nodes_Nodes_h
#include <cstdlib>
[Code]....
How to find the size of an array in called function? When we pass the array a argument to function definition we will be having base address of array, so my understanding is that we will not get the size of an array? but is there any hacking for this to find size of array other than passing as size an argument to this called function?
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