Urgent question

bcompt143 · #1 24-Aug-2008, 09:22

My C++ program is Turbo. When I write the following program my compiler display the following error, and I cant able to recognize my error. Please tell me some suggestion.

CPP / C++ / C Code:

#include<iostream.h>
#include<conio.h>
#include<string.h>
#define max 200

struct date {
	int day;
	int month;
	int year;
	};
struct school {
	char name[40];
	int rno;
	struct date dob;
	struct date doa;
	}student[max];
void output (school student, int n);
void sort (school student, int n);

int n;

void main ()
{
	int n;
	school student[max];
	cout<<"enter no of student"<<endl;
	cin>>n;
	for(int i=0; i<n; i++)
	{
	 cout<<"Name"<<endl;
	 cin>>student[i].name;
	 cout<<"roll number"<<endl;
	 cin>>student[i].rno;
	 cout<<"dob"<<endl;
	 cin>>student[i].dob.day;
	 cin>>student[i].dob.month;
	 cin>>student[i].dob.year;
	 cout<<"doa"<<endl;
	 cin>>student[i].doa.day;
	 cin>>student[i].doa.month;
	 cin>>student[i].doa.year;
	}
	cout<<"unsorted"<<endl;
	output(student, n);
	sort(student, n);
	cout<<"unsorted"<<endl;
	output(student, n);

	getch();
}
void output (school student[max], int n)
{
	cout<<"Name         rollnumber       dob     doa\n";
	cout<<"__________________________________________\n";
	for(int i=0; i<n; i++)
	{
	cout<<student[i].name<<'t';
	cout<<student[i].rno<<'t';
	cout<<student[i].dob.day<<'t';
	cout<<student[i].dob.month<<'t';
	cout<<student[i].dob.year<<'t';
	cout<<student[i].doa.day<<'t';
	cout<<student[i].doa.month<<'t';
	cout<<student[i].doa.year<<endl;
}
}
void sort(school student[max], int n)
{
	struct school temp;
	for(int i=0; i<n; i++)
	{
	 for(int j=i+1; j<n; j++)
	 {
	  if(strcmp(student[i].name, student[j].name) <=0)
	  {
	   temp=student[i];
	   student[i] = student[i];
	   student[j] = temp;
	  }
	 }
	}
}

The error are

Compiling SCHOOL.CPP:
Error SCHOOL.CPP 44: Cannot convert 'school *' to 'school' in function main()
Error SCHOOL.CPP 44: Type mismatch in parameter 'student' in call to 'output(school,int)' in function main()
Error SCHOOL.CPP 45: Cannot convert 'school *' to 'school' in function main()
Error SCHOOL.CPP 45: Type mismatch in parameter 'student' in call to 'sort(school,int)' in function main()
Error SCHOOL.CPP 47: Cannot convert 'school *' to 'school' in function main()
Error SCHOOL.CPP 47: Type mismatch in parameter 'student' in call to 'output(school,int)' in function main()

ocicat · #2 24-Aug-2008, 10:50

Quote:

Originally Posted by bcompt143

The error are

Compiling SCHOOL.CPP:
Error SCHOOL.CPP 44: Cannot convert 'school *' to 'school' in function main()
Error SCHOOL.CPP 44: Type mismatch in parameter 'student' in call to 'output(school,int)' in function main()
Error SCHOOL.CPP 45: Cannot convert 'school *' to 'school' in function main()
Error SCHOOL.CPP 45: Type mismatch in parameter 'student' in call to 'sort(school,int)' in function main()
Error SCHOOL.CPP 47: Cannot convert 'school *' to 'school' in function main()
Error SCHOOL.CPP 47: Type mismatch in parameter 'student' in call to 'output(school,int)' in function main()

The error is telling you exactly what is the problem. Line 44 is the following:

CPP / C++ / C Code:

output(student, n);

...yet the prototype for function output() states:

CPP / C++ / C Code:

void output (school student, int n);

The error message points out that the function expects a school instance, but you are passing it an array of school. Given that the function itself treats the incoming argument as an array as well, change the prototype to the following:

CPP / C++ / C Code:

void output (school student[], int n);

...& make the corresponding change in the function's parameter list.

Peter_APIIT · #3 03-Sep-2008, 02:55

Please learn array and pointer properly.

dlp · #4 03-Sep-2008, 07:38

Part of your problem is your code is a little unclear with the number of variables sharing the same name. Let me show you something with a stripped down version of your code:

CPP / C++ / C Code:

#include <iostream>
using namespace std;

const int MAX = 200;

struct date {
    int day;
    int month;
    int year;
};

struct school {
    char name[40];
    int rno;
    struct date dob;
    struct date doa;
} student[MAX];

int main()
{
    student[0].rno = 1;
    cout << student[0].rno << endl;
}

Now, I can reference student[0] without having written

CPP / C++ / C Code:

...
int main()
{
    school student[MAX];
...

due to the fact that you declare an array of school struct with this last bit of your struct definition:

CPP / C++ / C Code:

} student[MAX];

Now, when you have

CPP / C++ / C Code:

...
} student[MAX];

int main()
{
    school student[MAX];
...

Which array called student are you referring to throughout your program? Likewise, when you start saying:

CPP / C++ / C Code:

...
} student[MAX];

void output( school student, int n );
void sort( school student, int n );

int main()
{
    school student[MAX];
...

The compiler is going to be confused. For your functions, it's asking whether school student means a single variable of type school called student or is it saying that student means that array of school you created above is to be put in the function prototype?

Here's my question: Why have this line?

CPP / C++ / C Code:

} student[MAX];

at the end of your struct definition? What purpose does it serve? All it really is doing right now is confusing the compiler. Let's do this instead (replace any ... with your code):

CPP / C++ / C Code:

#include <iostream>
using namespace std;

const int MAX = 200;

struct date {
    int day;
    int month;
    int year;
};

struct school {
    char name[40];
    int rno;
    struct date dob;
    struct date doa;
}; // <- remove extra redefinition

void output( school student[], int n ); // <- use [] as ocicat suggested
void sort( school student[], int n );

// <- remove extra redefinition of int n as well

int main()
{
    int n;
    school student[MAX];

    ...
}

void output( school student[], int n ) // <- use [] as ocicat suggested
{
    ...
}

void sort( school student[], int n )
{
    ...
}

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Rate This Thread
Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Please, This is Difficult question try for me!	bcompt143	C++ Forum	4	24-Aug-2008 09:14
Urgent help regarding window service	slogeshwaran	Java Forum	2	14-Jul-2008 02:22
[GRAPHICS] - SymbolDesignerTool - URGENT HELP PLS	metan	Java Forum	0	15-Mar-2006 00:32
Urgent !question about read file(variable length)	robin1977	C Programming Language	2	13-Mar-2005 17:01
question of practice	magiccreative	C++ Forum	1	06-Feb-2004 07:17

Urgent question

Re: Urgent question

Re: Urgent question

Re: Urgent question