Thread: Function call

Code:

typedef struct{
		int ID;
		char name[50];
		double hor_total;
	}group;
	group salesman[SIZE];


void sale_menu();
void AddSalesMan();
int nextid();

void sale_menu(int menu)
{
	printf("Sales Processing System\n");
	printf("-----------------------\n\n");
	printf("1. Add Salesman Records\n");
	printf("2. Reports Generation\n");
	printf("3. Modify Salesman Records\n");
	printf("4. Delete Salesman Records\n\n");
	printf("0. Exit\n");
	printf("Your choice: ");
	scanf("%d", &menu);
}

void AddSalesMan()
{
	FILE *inSales;
	int a, b;


	if ( (inSales = fopen("sales.txt","a")) == NULL)
		printf("Cannot open sales.txt file.");
	else
	{
		fprintf(inSales,"\n");
		for(a=0; a<SIZE; a++)
		{
			fprintf(inSales,"S%04d|",salesman[a].ID);


			for (b=0; b<4; b++)
			{
				printf("Quarter %d: ",b+1);
				scanf(" %lf", &sale[a][b]);
				fprintf(inSales,"%lf|",sale[a][b]);
			}	
		}	
	}
	fclose(inSales);
}


int nextid(int currentId, int isReset)
{
	static int lastId = 0;
	if (isReset)
	{
		lastId = currentId;
	}
	return ++lastId;
	
}




// function main begins program executionvoid main()
{
	// file pointer for nextid.txt
	FILE *readId;
	// variable declaration
	int a, b, c = 0, last, getMenu = 0; 
	double ver_total = 0, max = 0; 
	int id = 0, lastId, resetId = 0;


	
	// if readId(open nextid.txt) is NULL, display message
	if ( (readId = fopen("nextid.txt","r")) == NULL)
		printf("Cannot open nextid.txt file");
	else
	{
		// read previous id numbering from nextid.txt
		fscanf(readId,"%d",&lastId);
		// Pass lastId and resetId arguments to nextid function call
		nextid(lastId, resetId);
	}
	// close readId file pointer
	fclose(readId);


	// Initialize salesman id and salesman horizontal total value
	for(a=0; a<SIZE; a++) 
	{
		salesman[a].ID = nextid(lastId, resetId);
		salesman[a].hor_total = 0;
	}


	// call sale_menu function
	sale_menu(getMenu);
	
	// if getMenu = 1, call AddSalesMan function
	if (getMenu == 1)
		AddSalesMan();
}

Why AddSalesMan() function cannot execute?

How to pass by reference?

Code:

#include <stdio.h>#include <stdlib.h>


int sale_menu();
int report_menu();
void QtrReport();


int sale_menu()
{
	int menu;
	printf("Sales Processing System\n");
	printf("-----------------------\n\n");
	printf("1. Add Salesman Records\n");
	printf("2. Reports Generation\n");
	printf("3. Modify Salesman Records\n");
	printf("4. Delete Salesman Records\n\n");
	printf("0. Exit\n");
	printf("Your choice: ");
	scanf("%d", &menu);
	return menu;
	printf("\n");
}


int report_menu()
{
	int report;
	printf("Reports Generation\n");
	printf("------------------\n\n");
	printf("1. View Quarterly Sales Report\n");
	printf("2. View Individual Salesman Commission\n\n");
	printf("0. Return to Main Menu\n");
	printf("Your choice: ");
	scanf("%d", &report);
	return report;
}


void QtrReport()
{
	printf("QtrReport\n");
	
}


// function main begins program execution
void main()
{
	// variable declaration
	int getMenu = 0, getReport = 0; 
	// call sale_menu function
	getMenu = sale_menu();
	printf("\n");
	// if getMenu = 1, call AddSalesMan function
	switch(getMenu)
	{
		case 1:
			break;


		case 2:
			report_menu();
			
			switch (getReport = report_menu())
			{
				case 1:
					QtrReport();
					break;
			}
			break;
	}


	system("pause");
	
}

select 2 then 1 two times to test it.

Why view Quarterly Sales Report function need to insert 2 times in order to execute? Can solve the issue without using pointer?

How soon you forget things! main returns int, not void!

Originally Posted by ulti-killer

select 2 then 1 two times to test it.

Why view Quarterly Sales Report function need to insert 2 times in order to execute? Can solve the issue without using pointer?

How many times are you calling report_menu()?

And you need pointers for scanf() and printf(), because printf technically takes a pointer to char as its first argument. I don't see anywhere else in your program that uses pointers. I don't understand what you are asking to "solve the issue without using pointer".

I change the main to int still the same result.

I plan to use while loop to loop report_menu() until the user wants to stop the program.

I mean the idea in post#5

My post#6 is same as u mention but it doesn't work well.

I need to input 2 times on Report Generation in order to execute QtrReport function.

Originally Posted by laserlight

If you do not want to pass a pointer to the menu selection, i.e., to use an out parameter, then just return the menu selection as an int, i.e., change your function to have an int return type (and change the calling code accordingly).

Is this overhead of passing the object by value will consume more memory?

All objects are passed by value in C - a pointer is also a type of object. Typically int is 4-8 bytes and a pointer is 4-8 bytes. These objects can also be loaded directly into a CPU register, in which case the "memory consumption" of such an object is zero.