file manipulation

[silvertooth07]

i'm having problems with my function: edit.

when i enter a name eventhough it exists, it always prints "File not found".

#include<iostream.h>
#include<fstream.h>
#include<conio.h>

void info()
{    
     cout << "               **********************************************" << endl;
     cout << "               *                 Case Study - 2             *" << endl;
     cout << "               *                   Phonebook                *" << endl;
     cout << "               *                   Y - 201                  *" << endl;
     cout << "               *                                            *" << endl;
     cout << "               *                                            *" << endl;
     cout << "               *                                            *" << endl;
     cout << "               *                                            *" << endl;
     cout << "               **********************************************" << endl;
}

struct node
{ 
        char name[30];
        char number[11];
        node *nxt;
};

node *start_ptr = NULL;
char option = ' ';

void add()
{
     
     
     node *temp, *temp2;
     temp = new node;
     
     cout << "\n\nPlease enter name: ";
     cin >> temp->name;
     cout << "Please enter number: ";
     cin >> temp->number;
          
     temp->nxt = NULL;
     
     if (start_ptr == NULL)
       { 
           start_ptr = temp;
       }
     else
       { 
           temp2 = start_ptr;
           while (temp2->nxt != NULL)
           {    
               temp2 = temp2->nxt;
           }
           temp2->nxt = temp;
       }
}

void add_to_file()
{
         ofstream outfile("Phone Book.txt");
         node *temp;
         temp = start_ptr;   
         
         while (temp != NULL)
         {
           outfile << temp->name << "\t";
           outfile << temp->number << endl;
           temp = temp->nxt;
         }
}   

void edit()
{
     node *temp;
     temp = start_ptr;
     char z[30];
     int found = 0;
     
     if(temp==NULL)
		cout << "Phonebook doesn't contain any stored numbers.\n";
     else
     {
         cout << "\nEnter name: ";
         cin >> z;
         
         while(temp!=NULL)
         {
                 if(temp->name == z)
                 {
                      cout << "Name: " << temp->name << "\tNumber: " << temp->number << endl << endl;
                      cout << "Enter new name:";
                      cin >> temp->name;
                      cout << "Enter new number: ";
                      cin >> temp->number;
                      found = 1;
                 }
                 temp=temp->nxt;
         }
         if (found==0)
            cout << "File not Found";
     }
}

int main()
{
    info();
    start_ptr = NULL;
    do
	{
     cout << endl;
     system("color 17");
     cout << "What do you want to do?: " << endl;
     cout << "\n1.   Add a contact" << endl; 
     cout << "\n2.   Delete a contact" << endl;
     cout << "\n3.   Edit a contact" << endl;
     cout << "\n4.   Search a contact" << endl;
     cout << "\n5.   Display contacts" << endl;
     cout << "\n6.   Exit" << endl << endl;

      cout << endl << " --->>> ";
      
	  option = getche();
	  
	  switch (option)
	    {
          case '1' : { add(); add_to_file(); break;}
	      //case '2' : del(); break;
	      case '3' : edit(); break;
	      //case '4' : search(); break;
	      //case '5' : display(); break;
          case '6': system("exit"); break;
         //default: cout<<"\nINVALID INPUT!!";
	    }
	    //if (option >= '1' && option <= '6')
           //display();      
	}
     while (option != '6');
    system("pause");
} 

thanks!^^

[guestgulkan]

if(temp->name == z)
You are comparing two char pointers.

As you are using char arrays for the name - you can use strcmp function.

Better still - if there is no real reason why you have to use char arrays then use C++ strings.

(And while you are at it - update your compiler - any compiler that uses iostream.h is old).

I'm pretty sure you are also going to have problems with your add_to_file function
in the way you are using the "Phone Book.txt" file.

[silvertooth07]

i don't know strcmp function. we didn't discuss it in our class. is there any way on how to search a node?

why? what will be the possible problem? i'm sorry, i'm just a beginner at c++ and i'm new at file manipulation. we didn't even try to do a simple program about file manip. T_T

i'm using dev-c++, that's what we're using in our school. it's just my habit, but we can also use using namespace std.

THANKS!

[guestgulkan]

i don't know strcmp function. we didn't discuss it in our class.

I would have thought that you would have at least done C strings (null terminated array of char)
before something like linked lists.
How do they expect you to search this particular linked list for a particular node using the name value????
Strange.

But for the record try this:

#include <stdio.h> //include this

if(strcmp (temp->name, z) ==0)//change your test line to this and see if that helps

[silvertooth07]

even linked list wasn't discussed thoroughly..

thanks for the strcmp, i will study about it. for now, i just made a new node (integer) so that it will be easier for me to compare and search for it.

i will also try what you suggested. thanks!^^