Strings Became Symbols When They Output in C -

i have problem when output strings in codes. when input 1 string , output it, there no problem @ all. but, when input @ least 2 strings, went fail. strings became symbols, except last one. here screenshot:

i've been using fflush(stdin) , fflush(stdout), problem still exist. so, should do? need advice.

here complete codes:

#include <stdio.h> #include <stdlib.h>  void menu(); void entry(); void search(); void printsingle(); void printcomplete(); float totalused(int i); float regularcost(int i); float tax(int i); float discount(int i); float totalpayment(int i);  #define nmaks 101  typedef enum {false=0,true=1} boolean; typedef struct {int billnumber,billclass;float lastmeter,currentmeter;char name[];} billdatabase; billdatabase bill[nmaks];  int dataamount=0;  int main() {      menu();     return 0; }  void menu() {      int i;      repeat:     system("cls");     printf("\t\t.: electric billing system :.\n\n");     printf("[1] entries customer information\n");     printf("[2] search customer\n");     printf("[3] print single bill\n");     printf("[4] print complete billing report\n");     printf("[5] exit\n\n");     printf("select menu[1..5]: ");scanf("%d",&i);      switch (i) {         case 1  :   entry();break;         case 2  :   search();break;         case 3  :   printsingle();break;         case 4  :   printcomplete();break;         case 5  :   {                     printf("\n\ngoodbye!");                     getch();                     break;         }         default :   {                     printf("\n\nwrong menu!");                     goto repeat;         }     } }  void entry() {      char repeat;      {         system("cls");         printf("\t\t.: electric billing system :.\n\n");         printf("[1] entries customer information\n\n");         dataamount++;         printf("bill number: ");scanf("%d",&bill[dataamount].billnumber);         printf("customer name: ");fflush(stdin);fflush(stdout);gets(bill[dataamount].name);         printf("class[1..3]: ");scanf("%d",&bill[dataamount].billclass);         printf("last meter: ");scanf("%f",&bill[dataamount].lastmeter);         printf("current meter: ");scanf("%f",&bill[dataamount].currentmeter);         printf("\nentry again[y/n]: ");repeat=getche();     } while (tolower(repeat)=='y');     menu(); }  void search() {      int i,bn;     boolean found;     char repeat;      {         system("cls");         printf("\t\t.: electric billing system :.\n\n");         printf("[2] search customer\n\n");         printf("enter bill number: ");scanf("%d",&bn);         found=false;         (i=1;i<=dataamount;i++)             if (bn==bill[i].billnumber) {                 found=true;                 break;             }         if (found) {             printf("\ncustomer found!\n\n");             printf("bill number\tn      m    e class\t\tlast meter\tcurrent meter\n");             fflush(stdin);fflush(stdout);             printf("%d\t\t%15.15s\t%d\t\t%.2f kwh\t%.2f kwh\n",bill[i].billnumber,bill[i].name,bill[i].billclass,bill[i].lastmeter,bill[i].currentmeter);         }         else             printf("\ncustomer not found!\n");         printf("\nsearch again[y/n]: ");repeat=getche();     } while (tolower(repeat)=='y');     menu(); }  void printsingle() {      int i,bn;     boolean found;     char repeat;      {         system("cls");         printf("\t\t.: electric billing system :.\n\n");         printf("[3] print single bill\n\n");         printf("enter bill number: ");scanf("%d",&bn);         found=false;         (i=1;i<=dataamount;i++)             if (bn==bill[i].billnumber) {                 found=true;                 break;             }         if (found) {             printf("\ncustomer found!\n\n");             printf("bill number\tn      m    e class\t\tlast meter\tcurrent meter\n");             fflush(stdin);fflush(stdout);             printf("%d\t\t%15.15s\t%d\t\t%.2f kwh\t%.2f kwh\n",bill[i].billnumber,bill[i].name,bill[i].billclass,bill[i].lastmeter,bill[i].currentmeter);             printf("total used\tregular cost\ttax\t\tdiscount\ttotal payment\n");             printf("%.2f kwh\t$%7.2f\t$%7.2f\t$%7.2f\t$%7.2f\n",totalused(i),regularcost(i),tax(i),discount(i),totalpayment(i));         }         else             printf("\ncustomer not found!\n");         printf("\nprint again[y/n]: ");repeat=getche();     } while (tolower(repeat)=='y');     menu(); }  void printcomplete() {      int i;      system("cls");     printf("\t\t.: electric billing system :.\n\n");     printf("[4] print complete billing report\n\n");     printf("bill number\tn      m    e\t\tclass\ttotal payment\n");     (i=1;i<=dataamount;i++) {         fflush(stdin);fflush(stdout);         printf("%d\t\t%15.15s\t\t%d\t$%.2f\n",bill[i].billnumber,bill[i].name,bill[i].billclass,totalpayment(i));     }     printf("\npress key main menu");     getch();     menu(); }  float totalused(int i) {      return bill[i].currentmeter-bill[i].lastmeter; }  float regularcost(int i) {      float price;      switch (bill[i].billclass) {         case 1  :   price=10.0;break;         case 2  :   price=7.5;break;         default :   price=13.75;     }     return totalused(i)*price; }  float tax(int i) {      float taxpercentage;      switch (bill[i].billclass) {         case 1  :   taxpercentage=1.5/100;break;         case 2  :   taxpercentage=0.25/100;break;         default :   taxpercentage=3.5/100;     }     return regularcost(i)-(regularcost(i)*taxpercentage); }  float discount(int i) {      float discountpercentage;      switch (bill[i].billclass) {         case 1  :   discountpercentage=3.0/100;break;         case 2  :   discountpercentage=2.0/100;break;         default :   discountpercentage=5.5/100;break;     }     if (regularcost(i)>100.0)         return regularcost(i)-(regularcost(i)*discountpercentage);     else         return 0.0; }  float totalpayment(int i) {      return regularcost(i)+tax(i)-discount(i); } 

note: use code blocks ide.

i see number of problems here.

first of all, over-use of global variables troubling. array bill , int dataamount should definitely not global. not c programming practice , not trust code looks this. please give "menu", "entry", "printcomplete", , "search" functions arguments can make these variables local, not global.

second, there few cases acceptable have many statements on same line in

 printf("customer name: ");fflush(stdin);fflush(stdout);gets(bill[dataamount].name); 

i'm getting headache looking @ it!!! pleeease don't!

third, not using array bounds correctly in loop, which cause of bug asking in first place.

 (i=1;i<=dataamount;i++) {     fflush(stdin);fflush(stdout);     printf("%d\t\t%15.15s\t\t%d\t$%.2f\n",bill[i].billnumber,bill[i].name,bill[i].billclass,totalpayment(i)); } 

remember, in c language, array indices start @ 0 , end @ "n - 1". loop starting @ 1 , ending @ "n".

the reason bogus character accessing billdatabase outside boundaries of array bill.

fourth, sami kuhmonen said, not allocating memory name array. although not causing bug seeing, cause program crash segmentation fault @ point in future. in order fix looming problem, have 2 options

1. the easy way out: change billdatabase struct following

   typedef struct {     int billnumber, billclass;     float lastmeter, currentmeter;     char name[128]; } billdatabase; 

   this easy, not good, because name can never more 128 chars. also, please don't ever put entire struct on 1 line. started hitting myself on head saxophone.

2. the harder way out: learn use malloc(), , manually allocate name arrays.