C++ cin/cout error

[Rahul Dixit]

I compile the following code, and get an error to do with the cin, cout operators. Basically I am trying to input parameters to a self made class using cin. However, the code does not recognise cin and cout for some reason??? :

#define PI 3.14
#define G 9.81;
#include <io.h>
#include <cmath>
#include <iostream>
using namespace std;

int main (void);

class pendulum
{ //data
double time;
int length;
double velocity;
int mass;
int energy;

//functions
public:
void run ();
double calculate_time();
double calculate_velocity();
};

double pendulum::calculate_time()
{ double input = length/G;
time = 2*PI*sqrt(input);
return time;
};

double pendulum::calculate_velocity()
{ double input = (2*energy)/mass;
velocity = sqrt(input);
return velocity;
};

void run ()
{ cout >> "time: ";
cin >> time;
cout >> "length: ";
cin >> length;
cout >> "velocity";
cin >> velocity;
cout >> "mass";
cin >> mass;
cout >> "energy";
cin >> energy;
};

and get the following error:
c:\documents and settings\vishal\my documents\visual studio 2005\projects\exercise 1\exercise 1\exercise_1.h(38) : error C2784: 'std::basic_istream<char,_Traits> &std::operator >>(std::basic_istream<char,_Traits> &,unsigned char &)' : could not deduce template argument for 'std::basic_istream<char,_Traits> &' from 'std::ostream'
C:\Program Files\Microsoft Visual Studio 8\VC\include\istream(1018) : see declaration of 'std::operator >>'
c:\documents and settings\vishal\my documents\visual studio 2005\projects\exercise 1\exercise 1\exercise_1.h(38) : error C2784: 'std::basic_istream<char,_Traits> &std::operator >>(std::basic_istream<char,_Traits> &,unsigned char &)' : could not deduce template argument for 'std::basic_istream<char,_Traits> &' from 'std::ostream'
.... and it continues on with the same message for the rest of the cins and couts...
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


I don't understand why the code does not recognise the cin and cout operators when iostream is clrealy included? Any insights here woud be much appreciated. Thank you for your time.

[jonnin]

I dont see an error. Try explicitly calling

cout.operator<<(variable) ; //syntax may not be 100%

and see if that helps any.

[evlich]

You have typos with the output stream operator. It should be:

cout << ...;
cin >> ...;

Hope this helps.

[Danny]

You have typos with the output stream operator. It should be:

cout << ...;
cin >> ...;

Hope this helps.

Precisely so!

Remember: cout support <<
cin supports >>

[Rahul Dixit]

You have typos with the output stream operator. It should be:

cout << ...;
cin >> ...;

Hope this helps.

thanks problem sorted..

[coolmads4u]

the following should work for u

#define PI 3.14
#define G 9.81
#include <io.h>
#include <cmath.h>
#include <iostream>
//#include <conio>
using namespace std;


class pendulum
{ //data
double time;
int length;
double velocity;
int mass;
int energy;

//functions
public:
double calculate_time()
{
double input = length/G;
time = 2*PI*sqrt(input);
return time;
}

double calculate_velocity()
{
double input = (2*energy)/mass;
velocity = sqrt(input);
return velocity;
}
void run()
{
cout<<"time: ";
cin>>time;
cout<<"length:";
cin>>length;
cout<<"velocity";
cin>>velocity;
cout<<"mass";
cin >> mass;
cout <<"energy";
cin >>energy;
}
};





void main()
{
pendulum p;
p.run();
}

[coolmads4u]

yeah the problem in ur program was u did not use
void pendulum::run()
{
.................
}
and u were terminating the function definetion using semicolon

the following code should help u...
[B]#define PI 3.14
#define G 9.81
#include <io.h>
#include <cmath>
#include <iostream>
using namespace std;

class pendulum
{ //data
double time;
int length;
double velocity;
int mass;
int energy;

//functions
public:
void run ();
double calculate_time();
double calculate_velocity();
};

double pendulum::calculate_time()
{
double input = length/G;
time = 2*PI*sqrt(input);
return time;
}

double pendulum::calculate_velocity()
{ double input = (2*energy)/mass;
velocity = sqrt(input);
return velocity;
}

void pendulum::run ()
{
cout << "time: ";
cin >> time;
cout << "length: ";
cin >> length;
cout << "velocity";
cin >> velocity;
cout << "mass";
cin >> mass;
cout << "energy";
cin >> energy;
}[/B]
void main()
{
pendulum p;
p.run();
}

regards
maddy!