wads wrong with my programe

[comput14]

can some 1 help me solve this error and warning.. this is the programe


#include <iostream>
#include <cstdlib>
using namespace std;

bool palindromes(long no);

int main ()
{
long num;

if (palindromes(num)==true)
{
cout<<num;
cout<<" is a palindrome.";
}

else
{

cout<<num;
cout<<" is not a palindrome.";
}

cout<<endl;
system("pause");
return 0;
}

bool palindromes(long no)
{
long num, quation, remainder,RN;

cout<<"Input a number to check if it is palindrome -> ";
cin>>num;

quation=num;
RN=0;
do
{
remainder=quation%10;
quation=quation/10;

RN=RN*10+remainder;
}

while (quation!=0);

if (num==RN)
{
return true;
}

else
{
return false;
}
}

i cant cout the correct number imputed

[jdd]

You have a problem with scope. The num in your palindromes function is not the same and the num in main, and you never initialize num in main.

[comput14]

how to initialize num in the main .. can u help me

[jdd]

Heres' a short bit on scope of variables: http://www.cplusplus.com/doc/tutorial/functions/

You could use pass by reference, so that your function modifies the same variable. You could also move

cout<<"Input a number to check if it is palindrome -> ";
cin>>num;

into main and then pass the value to the function.

[comput14]

can u teach me how to pass the value to the function as i was nt taught b4

[jdd]

Again, I will refer you to the Functions tutorial. http://www.cplusplus.com/doc/tutorial/functions/
It has explanations and examples of parameter usage, which is how data are passed to functions.

[comput14]

oic is this example right ???

#include <iostream>
using namespace std;

void duplicate (int& a, int& b, int& c)
{
a*=2;
b*=2;
c*=2;
}

int main ()
{
int x=1, y=3, z=7;
duplicate (x, y, z);
cout << "x=" << x << ", y=" << y << ", z=" << z;
return 0;
}

[jdd]

Yes, that is a good example of pass by reference. Using that technique, you should be able to rewrite your original program so that it does exactly what you want.