Strcmp help

[Rellicea]

Hi,

The problem I am currectly having is with the string function strcmp. I am trying to compare an array of 10 codes with a user inputted code, so when the strcmp finds the user inputted code in the array it can then edit that field in the array. So basically a process to search for a code and then edit that code in the array.

I'm not quite sure how to do all that but I have attempted the strcmp unsuccesfully, I keep getting the error:

'error C2664: 'strcmp' : cannot convert parameter 1 from 'char [10][7]' to 'const char *'

Here is my code, the code array is located above main and the function in question is 'reserve':

#include "stdafx.h"
#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>
#include <conio.h>
#include <iomanip.h>
#include <string.h>
//Function declarations
void getData (ifstream &inFile, float price[], int stands[]);
void menu1 ();
void reserve (int stands[]);
void remove (int stands[]);
void menu2 ();
char code[10] [7], des[10] [41];
int main(int argc, char* argv[])
{
ifstream inFile; //declaration for input file
float price[10]; //declaration for the cost
int stands[10]; //declaration for the ampunt of stands available
int menu_choice, menu_choice2;
cout << "Welcome to the Reservation Program for Trade Fairs Ltd" <<endl; //welcome message
inFile.open ("L:\\C++\\file.txt",ios::in/ios::nocreate); //opening the external file
if (!inFile) //check if file opens correctly
{
cout <<"\n\nUnable to open file!" << endl; //error message if file cant be opened
exit(2); //exit the program
}
else
{
getData (inFile, price, stands); //call function to retrieve data from file
}

menu1 (); //call 1st menu function
cin>> menu_choice; //read in users menu choice

//while ((menu_choice != '1')&&(menu_choice != '2'));
switch (menu_choice) //switch case menu
{
case 1: reserve (stands); //call function to reserve a stand
break;
case 2: remove (stands); //call function to reserve a stand
break;
default: cout<<"Invalid Option"<<endl;
return 0;
}


menu2 (); //call 2nd menu fuction
cin>> menu_choice2; //read in user choice
switch (menu_choice2) //switch case menu
{
case 1: system("CLS"); //clear screen
menu1 (); //call 1st menu function
break;
case 2: "\n\n**Program Terminates**\n"; //end program
break;
//error message for invalid character input
default: cout<<"Invalid Option"<<endl;
}
return 0;
}

//function to read data from a file and place it into an array
void getData (ifstream &inFile, float price[], int stands[]) //Function header parameter list including variables
{
int i; //decalartion for array sub
cout<<""<<endl;
cout<<setw(1)<<"Code"<<setw(8)<<"Price"<<setw(8)<<"Stands"<<setw(35)<<"Description"<<endl;
for (i = 1; i <10; i ++) //do loop 10 times, increment each time
{

inFile>>code; //read in fair code
inFile>>price; //read in price
inFile>>stands; //read in available amount of stands
inFile.get(); //use .get function for the description as it contains spaces
inFile.get(des, 39); //read in description
inFile.get ();
cout<<setw(6)<<code<<setw(5)<<price<<setw(5)<<stands<<setw(40)<<des<<endl;
}
inFile.close(); //close file
cout<<""<<endl;
}

//function to display a menu for the user to choose whether they would to reserve or remove a stand
void menu1 ()
{
cout<<"1.Make a reservation"<<endl; //menu text
cout<<"2.Remove a reservation"<<endl; //menu text

cout<<"Input your choice"<<endl; //instructions for menu
}

//function to reserve a stand, user inputs which fair to reserve for, then states how many stands to reserve
//that number is then removed from the available number of stands
void reserve (int stands[]) //function header paramater list with variables
{
char code_user[7];
int user_reserve; //declaration for user inputted number
cout<<"Please insert event code"<<endl; //user instructions
cin>>code_user; //read in fair code
if (strcmp (code, code_user) != 0)
{
cout<<"Please insert the number of stands you would like to reserve"<<endl; //user instructions
cin>>user_reserve; //read in amount to reserve
stands = stands - user_reserve; //calculation to add removed stands to the number of available stands
}
else
{
cout<<"Incorrect code"<<endl;
}
}


//function to remove a reservation, user inputs which fair to remove for, then states how many stands to remove
//that number is then added to the available number of stands
void remove (int stands[]) //function header paramater list with variables
{
int user_remove; //declaration for user inputted number
char code_user[7];
cout<<"Please insert event code"<<endl; //user instructions
cin>>code_user; //read in fair code
cout<<"Please insert the number of stands you would like to reserve"<<endl; //user instructions
cin>>user_remove; //read in amount to reserve
stands = stands + user_remove; //calculation to remove reserved stands from number of available stands
}

//function to write array to a file
void write_file_data (ofstream &outFile)
{
int i; //declartion of array sub
for (i = 1; i <11; i ++) //do 10 times
{
outFile<<code; //read array into file
if (i <10)
{
outFile<< endl; // write end of record marker
}
}
}

//function to display a menu to ask the user whether to make more changes or quit
void menu2 ()
{
cout<<"1.Make more changes"<<endl; //menu text
cout<<"2.Exit"<<endl; //menu text

cout<<"Input your choice"<<endl; //user instruction
}

Any help would be much apprecited, thanks

Regards
Chris Rice

 

[Salem]

1. Please use [code][/code] tags when posting code.

2. 'error C2664: 'strcmp' : cannot convert parameter 1 from 'char [10][7]' to 'const char *'
Without some kind of indication in the listing, like
// This is the line which errors
Few people will even bother to look at your code.

FYI, I think you need to do
[tt]if (strcmp (code[pos], code_user) != 0)[/tt]
But that would imply some kind of loop to check each code in the array.

> #include <stdlib.h> <- this is a C header
> #include <conio.h> <- this is a DOS header
> #include <iomanip.h> <- this is an OLD C++ header.
Something this simple should not need such a wide variety of headers.

--

 

[Rellicea]

Thanks for your reply, sorry about not using tags or indicating where the error lies.

I'll looking into incorpating your help into a for loop and see how I go.

As for the headers, I was instructed by someone to include those headers and have been taught to use them when performing some of the tasks including in the program.

 

[Rellicea]

I have implemented changes and the program now compiles, however no matter what code I search for the program accepts it, so even if I input an invalid code the program accepts it as correct.

Here is the function:

void reserve (int stands[])  //function header paramater list with variables
{
char code_user[7];
int user_reserve, i;   //declaration for user inputted number
for (i = 0; i <9; i ++)
{
  cout<<"Please insert event code"<<endl;  //user instructions
  cin>>code_user;    //read in fair code
    if (strcmp (code[i], code_user) != 0)
	{
       cout<<"Please insert the number of stands you would like to reserve"<<endl;   //user instructions
       cin>>user_reserve;   //read in amount to reserve
       stands = stands - user_reserve; //calculation to add removed stands to the number of available stands
	   break;
	}
    else 
	{
	   cout<<"Incorrect code"<<endl;
	}
}
}

Any ideas anyone? It's certainly progress on the way it was before but I'm stumped as to why the strcmp isn't working.

 

[cpjust]

Shouldn't your strcmp() be comparing against == 0 instead of != 0

0 means the strings are identical.
Anything other than 0 means they are different.

 

[Rellicea]

Thanks cpjust

I've fixed that oversight and it now works, however not perfectly. The function works fine if a correct code is input however if an incorrect code is input then the error message is displayed 8 times then the loop is left

void reserve (int stands[])  //function header paramater list with variables
{
char code_user[7];
int user_reserve, i;   //declaration for user inputted number
  cout<<"Please insert event code"<<endl;  //user instructions
  cin>>code_user;    //read in fair code
for (i = 0; i <9; i ++)
{
    if (strcmp (code[i], code_user) == 0)
	{
       cout<<"Please insert the number of stands you would like to reserve"<<endl;   //user instructions
       cin>>user_reserve;   //read in amount to reserve
       stands[i] = stands[i] - user_reserve; //calculation to add removed stands to the number of available stands
	   cout<<stands[i]<<endl;
	   break;
	}
	else
	{
     if (i <8)
	 {
       cout<<"Incorect code"<<endl;
	 }
	}
}

}

Any ideas how I can fix this?

 

[Salem]

bool found = false;
for (i = 0; i <9; i ++)
{
    if (strcmp (code[i], code_user) == 0)
    {
       cout<<"Please insert the number of stands you would like to reserve"<<endl;   //user instructions
       cin>>user_reserve;   //read in amount to reserve
       stands[i] = stands[i] - user_reserve; //calculation to add removed stands to the number of available stands
       cout<<stands[i]<<endl;
       found = true;
       break;
    }
}
if ( ! found ) {
  // message
}

--

 

[ArkM]

Tastes differs but in that program case I prefer this pattern:

int i;
for (i = 0; i < 9 && strcmp(code[i],code_user; ++i)
   ;
if (i >= 9)
{
... Not found reaction ...
}

Let the loop makes its job (array scan). The reaction is not a logical part of this loop body...