Field Access

The dot operator reads or writes a field inside a struct value.

field_access.c

#include <stdio.h>

struct Account {
    int balance;
    int limit;
};

int main(void) {
    int deposit = ;
    struct Account account = {20, 30};

    account.balance = account.balance + deposit;

    printf("balance=%d\n", account.balance);
    return 0;
}

#include <stdio.h>

struct Account {
    int balance;
    int limit;
};

int main(void) {
    int deposit = ;
    struct Account account = {20, 30};

    account.balance = account.balance + deposit;

    printf("balance=%d\n", account.balance);
    return 0;
}

#include <stdio.h>

struct Account {
    int balance;
    int limit;
};

int main(void) {
    int deposit = ;
    struct Account account = {20, 30};

    account.balance = account.balance + deposit;

    printf("balance=%d\n", account.balance);
    return 0;
}

dot operator `account.balance` selects the `balance` field of `account`.

update field Assigning to a field changes only that part of the struct.