Multiple function output

**Dark Nemesis** · 08-10-2003

it's fairly simple, I'd like to output more than one variable from a function to the main program, but I can't think of anyway to get this to happen.

**oobootsy1** · 08-10-2003

i dunno

**ygfperson** · 08-10-2003

The simplest way is to put it into a struct or class.

Code:

struct Object {
  int x;
  float y;
};

Object func() {
  Object o;
  o.x = 3;
  o.y = 4.4;
  return o;
}

Or, you could pass the arguments by reference and manipulate them there:

Code:

void func(int& x, float& y) {
  x = 3;
  y = 4.4;
}
int main () {
  int x;
  float y;
  func(x,y);
  
  return 0;
}

**funkydude9** · 08-10-2003

A class, or struct, is a good way to pass alot of information to a function. If you just want to pass two variables, you just do:

Code:

void Output(int x, char ch)
{
cout<<x<<endl;
cout<<ch<<endl;
}

**Dark Nemesis** · 08-10-2003

Yes I understand that, however, with the function it both 1) takes variables from int main() and 2) requires to output numerous variables. I thought about putting the varaibles in individual functions for transfer, but int main() needed to give the functions new values

.

I guess I should have mention I needed to both input and output in the first post...

**JaWiB** · 08-10-2003

Not sure I understand...did you look at ygf's code (modified a bit):

Code:

void func(int& x, float& y) {
  x = 3;
  y = 4.4;
}
int main () {
  int x=1;
  float y=2;
  cout<<"X:\t"<<x<<endl;
  cout<<"Y:\t"<<y>>endl;
  func(x,y);
  cout<<"X:\t"<<x<<endl;
  cout<<"Y:\t"<<y<<endl;
  return 0;
}

**7stud** · 08-10-2003

....or if the data you want to return is all the same type, you can just pass your function an array:

Code:

#include<iostream>
using namespace std;

void func(int a[])
{
	a[0]=10;
	a[1]=30;
} 

int main()
{
	int a[2]={0};
	func(a);

	for(int i=0; i<3; i++)
		cout<<a[i]<<endl;

	return 0;
}

**funkydude9** · 08-10-2003

You don't have to pass variables to a function, just declare them inside the function:

Code:

void Output()
{
     int x;
     cin>>x;
     cout<<x;
} //x does not exist anymore

7stud,

Code:

for(int i=0; i<2; i++)

**7stud** · 08-10-2003

...or if the data types you want to return are different you could do this:

Code:

#include<iostream>
using namespace std;

void func(int* i, double* d)
{
	*i = 50;
	*d = 2.75;
} 

int main()
{
	int* i;
	int my_int = 0;
	i=&my_int;

	double* d = 0;
	double my_double = 0;
	d = &my_double;

	func(i, d);

	cout<<*i<<endl<<*d<<endl;

	return 0;
}

**7stud** · 08-10-2003

funkydude9,

Please read the question more carefully. You certainly can't return statically allocated variables from a function.

**funkydude9** · 08-10-2003

funkydude9,

Please read the question more carefully. You certainly can't return statically allocated variables from a function.

Huh? I didn't say you could. From his question, it sounded like he didn't want to pass the variables to the function....

**Dark Nemesis** · 08-10-2003

the first example 7stud gave (after my second post) is very close to what I want. In the same function I input and output the variables and during the function's run, the varaibles change, and so I must update the values of the variables in int main() to match the ones in the function one the function finished, and the function (once run twice) will have to have the update variables.

Quick eg:

Code:

function(int a, int b){
a * 2;
b / 4;
}

int main() {
int a, b;
a = 1;
b = 8;

function(a,b);
// code to get variable values from function()
cout << a << b <<endl;

function(a,b);
// code to get variable values from function()
cout << a << b <<endl;

return 0;
}

**funkydude9** · 08-10-2003

Just pass them by refrence like so:

Code:

void function(int &a, int &b){
a = a* 2;
b = b/ 4;
}

There's no need for you to call it twice. Just output it once before you call the function, then output it after.
::EDIT::
whoops! Fixed your function, too.

**Dark Nemesis** · 08-10-2003

I would want to call it twice to update the variables
b should have been = to 16, sorry, but
wanted output from eg program:

24
41

reason:
first line the function would doulbe a (1-->2) and devide b by a quarter (16 --> 4), ten output the value of a then b with no space giving 24, then repeat the equation with the new values (2 --> 4) and (4--> 1)

the comments should be replace with what ever code is need to grab the variables from the function, and yes i did modify the function and test the program, it gave:

116
116

**funkydude9** · 08-10-2003

would want to call it twice to update the variables

Use recursion (calling the same function within a function) and then use an if statement to check if you have the desired values.

Thread: Multiple function output

Thread Tools

Search Thread

Display

Multiple function output

Similar Threads

dllimport function not allowed

How to fix misaligned assignment statements in the source code?

Please Help - Problem with Compilers

Contest Results - May 27, 2002

qt help