CODEWITHSUNDEEP
cstructmember
RandomNumberFun
RandomNumberFun

Reputation: 642

C: Having trouble troubleshooting why two of members of this struct is not incremeting correctly?

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define RECORDS 2
int main() {
    typedef struct {
        char firstName[30];
        char lastName[30];
        char street[35];
        char city[20];
        char state[3];
        int  zip;
        char phone[15];

        int  accountId;
    } Customer ;
    Customer customerArray[RECORDS];    


    typedef int records;
    records i = 0;  

    printf("================================================================\n");
    for(i = 0; i < RECORDS; ++i)
    {   

        printf("Enter data for customer %d\n", i + 1);
        printf("Enter firstname, last name, phone\n");
        scanf("%s %s %s", customerArray[i].firstName, customerArray[i].lastName, customerArray[i].phone);
        scanf("%*c");   

        printf("Enter Address (Street City State ZIP\n");
        scanf("%s %s %s %d", customerArray[i].street, customerArray[i].city, customerArray[i].state, &customerArray[i].zip);
        scanf("%*c");   

    }   


    for(i = 0; i < RECORDS; ++i) {
        char input[3]= {'\0'};
        printf("please enter state:\n");
        scanf("%s",input);  

        int strcmp(const char *s1, const char *s2);
        int strncmp(const char *s1, const char *s2, size_t n);
        char *custstate = customerArray[i].state;
        char *statelookup = input;


        if (strcmp(custstate, statelookup) == 0) {
        printf("\nData for customer number:%s", customerArray[i].accountId);
        printf("\nAccount:%s", customerArray[i].accountId);
        printf("\n Name:%s %s",customerArray[i].firstName, customerArray[i].lastName);
        printf("\nAddress:%s %s %s %d",customerArray[i].street, customerArray[i].city, customerArray[i].state, customerArray[i].zip);
        printf("\nPhone:%s",customerArray[i].phone);    

        }
        else
            printf("Could not find a match");

    }
    return 0;   


}

Having trouble figutring out why one of member of this struct is not incremeting correctly. The account id produces inaccurate output. and also the customer number is not producing correctly. e.g 1, 2 ect..

The output for said members looks like this...

Data for customer number:1606416396 Account:1606416396

Where it should look like

Data for customer 1 Account 1

Not sure what I am doing wrong. Still learning C. Total noob. any help would be greatly appreciated!

I am thinking I have to null terminate the members. But not sure if that's true or even how.

Upvotes: 1

Views: 127

Answers (2)

Barath Ravikumar
Barath Ravikumar

Reputation: 5836

All Variables , you use in your program reside mainly in two areas

  1. The Stack Segment
  2. The Data Segment

By Default , all automatic program variables and Structure variable are , stored onto the stack , and hence like all stack variables , they are not initialized by the compiler , and hence will contain an unpredictable value , usually known as a junk value.So it is always better to initialize variables explicitly during declaration.

The variables which mainly reside in Data Segment are mostly Global and Static variables. These variables are automatically initialized to 0 , during declaration , so you won't find any junk value.

Example 

static int i =0;

is the same as

static int i;

Do take a look at this page , for more info

http://www.geeksforgeeks.org/memory-layout-of-c-program/

Upvotes: 0

Patashu
Patashu

Reputation: 21773

You never initialize the field accountId. In C, instead of getting a error for using an uninitialized field, it just uses a random value (because the RAM will have a random value from whatever memory was last there). So, the huge meaningless value is explained as being a leftover from some other program. To fix this, you have to set it to something before accessing it.

Upvotes: 3

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