Insert Node at the End in Singly Linked List

//insert at end

void single_linked_list::insert_at_end(int element)

{

    if(first_node == NULL)

    {

        //printf("List is empty, end and beginng is same \n");

        node* new_node = new node();

        new_node->data = element;

        new_node->link = NULL;

        first_node =  new_node;

    }

    else

    {

        node* temp_node = first_node;

        node* new_node = new node();

        new_node->data = element;

        new_node->link = NULL;

        while(temp_node->link)

        {

            temp_node = temp_node->link;

        }

        temp_node->link  = new_node;

    }

}