Customer Billing System Project Summary:
Although graphics are not used in this Customer Billing System Project, the application of user-defined functions and structures has been quite beneficial. The following are the main user-defined functions used in this C project:
void input()
writefile ()
Void Search()
void output()
void input() function is used to create a new customer account in the system, i.e., with the help of this function, the parameters like name, address, phone number, amount to be paid, etc. are requested and entered.
Another void writeFile() function is used to create a file on the computer’s hard drive to store client information and data.
The void search() function is used to search for previously stored accounts by name or customer number.
The fourth and final user-defined function used in this C Customer Billing System project is void output(), which is defined to display the result as console output. Contact Management System using C with Source code similar to project
In customer billing systems, structures have been used very well to group types of data into a single entity. Date variables (day, month and year) are grouped into structures called date while other variables like name, number, street, the amount paid, etc. are called date variables. They are grouped into another structure called Accounts.
The customer Billing System App is very easy to use. To use the application, click on the exe file and then, you will have three options:
- to add account
- to find account
- To Live
The specialty of the Customer Billing System
- You can add an unlimited number of accounts and new accounts can be added at any time.
- Simple calculations, such as the calculation of dues, balances, etc., are programmed into the project code.
- The Customer Billing System in C Project allows you to view an account using one of two methods: Customer Name or Customer Number.
- The amount to be paid is shown as a negative balance.
- You can quickly exit the software from the main menu if you don’t need it.
Customer Billing System using C Language Source code
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void input();
void writefile();
void search();
void output();
struct date{
int month;
int day;
int year;
};
struct account {
int number;
char name[100];
int acct_no;
float mobile_no;
char street[100];
char city[100];
char acct_type;
float oldbalance;
float newbalance;
float payment;
struct date lastpayment;
}customer;
int tl,sl,ts;
void main()
{
int i,n;
char ch;
clrscr();
_setcursortype(_NOCURSOR);
printf(" CUSTOMER BILLING SYSTEM:\n\n");
printf("===============================\n");
printf("\n1: to add account on list\n");
printf("2: to search customer account\n");
printf("3: exit\n");
printf("\n================================\n");
do{
printf("\nselect what do you want to do?");
ch=getche();
}while(ch<='0' || ch>'3');
switch(ch){
case '1':
clrscr();
printf("\nhow many customer accounts?");
scanf("%d",&n);
for(i=0;i<n;i++){
input();
if(customer.payment>0)
customer.acct_type=(customer.payment<0.1*customer.oldbalance)? 'O': 'D';
else
customer.acct_type=(customer.oldbalance>0)?'D' : 'C';
customer.newbalance=customer.oldbalance - customer.payment;
writefile();
}
main();
case '2':
clrscr();
printf("search by what?\n");
printf("\n1 --- search by customer number\n");
printf("2 --- search by customer name\n");
search();
ch=getche();
main();
case '3':
clrscr();
delay(700);
textcolor(RED);
gotoxy(25,25);
cprintf("\nA PROJECT BY BIDUR & SUJAN");
delay(1500);
exit(1);
}
}
void input()
{
FILE *fp=fopen("bidur.dat","rb");
fseek (fp,0,SEEK_END);
tl=ftell(fp);
sl=sizeof(customer);
ts=tl/sl;
fseek(fp,(ts-1)*sl,SEEK_SET);
fread(&customer,sizeof(customer),1,fp);
printf("\ncustomer no:%d\n",++customer.number);
fclose(fp);
printf(" Account number:");
scanf("%d",&customer.acct_no);
printf("\n Name:");
scanf("%s",customer.name);
printf("\n mobile no:");
scanf("%f",&customer.mobile_no);
printf(" Street:");
scanf("%s",customer.street);
printf(" City:");
scanf("%s",customer.city);
printf(" Previous balance:");
scanf("%f",&customer.oldbalance);
printf(" Current payment:");
scanf("%f",&customer.payment);
printf(" Payment date(mm/dd/yyyy):");
scanf("%d/%d/%d",&customer.lastpayment.month,&customer.lastpayment.day,&customer.lastpayment.year);
return;
}
void writefile()
{
FILE *fp;
fp=fopen("bidur.dat","ab");
fwrite(&customer,sizeof(customer),1,fp);
fclose(fp);
return;
}
void search()
{
char ch;
char nam[100];
int n,i,m=1;
FILE *fp;
fp=fopen("bidur.dat","rb");
do{
printf("\nenter your choice:");
ch=getche();
}while(ch!='1' && ch!='2');
switch(ch){
case '1':
fseek(fp,0,SEEK_END);
tl=ftell(fp);
sl=sizeof(customer);
ts=tl/sl;
do{
printf("\nchoose customer number:");
scanf("%d",&n);
if(n<=0 || n>ts)
printf("\nenter correct\n");
else{
fseek(fp,(n-1)*sl,SEEK_SET);
fread(&customer,sl,1,fp);
output();
}
printf("\n\nagain?(y/n)");
ch=getche();
}while(ch=='y');
fclose(fp);
break;
case '2':
fseek(fp,0,SEEK_END);
tl=ftell(fp);
sl=sizeof(customer);
ts=tl/sl;
fseek(fp,(ts-1)*sl,SEEK_SET);
fread(&customer,sizeof(customer),1,fp);
n=customer.number;
do{
printf("\nenter the name:");
scanf("%s",nam);
fseek(fp,0,SEEK_SET);
for(i=1;i<=n;i++)
{
fread(&customer,sizeof(customer),1,fp);
if(strcmp(customer.name,nam)==0)
{
output();
m=0;
break;
}
}
if(m!=0)
printf("\n\ndoesn't exist\n");
printf("\nanother?(y/n)");
ch=getche();
}while(ch=='y');
fclose(fp);
}
return;
}
void output()
{
printf("\n\n Customer no :%d\n",customer.number);
printf(" Name :%s\n",customer.name);
printf(" Mobile no :%.f\n",customer.mobile_no);
printf(" Account number :%d\n",customer.acct_no);
printf(" Street :%s\n",customer.street);
printf(" City :%s\n",customer.city);
printf(" Old balance :%.2f\n",customer.oldbalance);
printf(" Current payment:%.2f\n",customer.payment);
printf(" New balance :%.2f\n",customer.newbalance);
printf(" Payment date :%d/%d/%d\n\n",customer.lastpayment.month,customer.lastpayment.day,customer.lastpayment.year);
printf(" Account status :");
textcolor(128+RED);
switch(customer.acct_type)
{
case 'C':
cprintf("CURRENT\n\n");
break;
case 'O':
cprintf("OVERDUE\n\n");
break;
case 'D':
cprintf("DELINQUENT\n\n");
break;
default:
cprintf("ERROR\\n\n");
}
textcolor(WHITE);
return;
}
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