Question

I am passing a char array by reference but when I return from function and print the array, it displays nothing. What am I doing wrong?

#include <iostream>

using namespace std;

void func(char []);
int main()
{
   char a[100];
   func(a);

   cout << a<<endl;
   return 0;
}

void func(char *array)
{
   array="Inserting data in array a";
   cout << array<<endl;
}

Regards

Answer 1

You’re not passing the array by reference (nor should you, it will do you no good here). You are passing a pointer to its first element. You then reassign that pointer to point to something else inside the function. This has no effect on the array. If you want to change the contents of the array, then you need to copy data to the place that the pointer points to. You can use strcpy or similar for that:

strcpy(array, "Inserting data in array a");

As a side comment, but a very important one. We don’t need to deal with things like this in C++ anymore. That’s how you do things in C. Here’s how we do things in C++:

#include <string>
#include <iostream>

void func(std::string & str)
{
    str = "Inserting data into the string";
    std::cout << str << std::endl;
}

int main()
{
    std::string a;
    func(a);
    std::cout << a << std::endl;
}