Зміст курсу

C Structs

1. Introduction to Structs

What are Structs Structs Application Defining and Declaring Structs Creating Your First Struct Accessing Struct Fields

2. Pointers and Structs

Pointers Brief Overview Pointers to Structs Pointers Inside Structs Dynamically Allocating Structs Passing Structs to the Functions

3. Structs and Memory

Understanding Memory Layout of Structs Alignment and Padding in Structs Unions Arrays with Structs

4. Advanced Structs Usage

Nested Structs Struct with Arrays and Other Structs Anonymous Struct and Union Complex Data Structure

5. Implementing Data Structures

Introduction to Linked List Basic Concept and Structure Building a Linked List Travesting and Displaying Linked List Completion Overview

Passing Structs to the Functions

Functions can work with structures just like with regular variables:

main


              123456789101112131415161718192021
            
#include <stdio.h>

// structure definition
typedef struct {
    char name[50];
} Person;

// function to display information about a person
void printPerson(Person p) {
    printf("Name: %s\n", p.name);
}

int main() {
    // creating a structure and initializing its values
    Person person1 = {"John"};

    // call a function to display information about a person
    printPerson(person1);

    return 0;
}

In order for a function to "interact" with a structure, for example, change the fields of an existing structure, the function must accept a pointer to the structure:

main


              12345678910111213141516171819202122232425262728293031
            
#include <stdio.h>

// structure definition
Typedef struct {
    char symbol;
}Example;

// function for changing the values of structure fields via a pointer
void changePoint(Example* ptr, int newSymbol)
{
    // check for NULL pointer
    if (ptr != NULL)
    {
        ptr->symbol = newSymbol;
    }
}

int main() {
    // create the Example structure and a pointer
    Example ptr1 = {'H'};
    Example* ptr = &ptr1;

    printf("Old symbol: %c | %p\n", ptr1.symbol, &ptr1);

    // use function to change the field of structures
    changePoint(ptr, 'y');

    printf("New symbol: %c | %p\n", ptr1.symbol, &ptr1);

    return 0;
}

Structures can be created inside functions, and such structures can "live" outside the functions (not locally) if the function returns a pointer to such a structure:

main


              1234567891011121314151617181920212223242526272829303132
            
#include <stdio.h>
#include <stdlib.h>

// structure definition
typedef struct {
    int value;
}Example;

// function creates a structure with the given field
Example* CreateStruct(int setVal)
{
    Example* ptr = (Example*)malloc(sizeof(Example));

    // check for successful memory allocation
    if (ptr != NULL)
    {
        ptr->value = setVal;
        return ptr;
    }
}

int main() 
{
    // use function to create structure 
    Example* ptrToStruct = CreateStruct(23);

    printf("Value inside struct: %d", ptrToStruct->value);

    free(ptrToStruct); // free memory

    return 0;
}

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Перейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів

Все було зрозуміло?

Секція 2. Розділ 5

Passing Structs to the Functions

Functions can work with structures just like with regular variables:

main


              123456789101112131415161718192021
            
#include <stdio.h>

// structure definition
typedef struct {
    char name[50];
} Person;

// function to display information about a person
void printPerson(Person p) {
    printf("Name: %s\n", p.name);
}

int main() {
    // creating a structure and initializing its values
    Person person1 = {"John"};

    // call a function to display information about a person
    printPerson(person1);

    return 0;
}

In order for a function to "interact" with a structure, for example, change the fields of an existing structure, the function must accept a pointer to the structure:

main


              12345678910111213141516171819202122232425262728293031
            
#include <stdio.h>

// structure definition
Typedef struct {
    char symbol;
}Example;

// function for changing the values of structure fields via a pointer
void changePoint(Example* ptr, int newSymbol)
{
    // check for NULL pointer
    if (ptr != NULL)
    {
        ptr->symbol = newSymbol;
    }
}

int main() {
    // create the Example structure and a pointer
    Example ptr1 = {'H'};
    Example* ptr = &ptr1;

    printf("Old symbol: %c | %p\n", ptr1.symbol, &ptr1);

    // use function to change the field of structures
    changePoint(ptr, 'y');

    printf("New symbol: %c | %p\n", ptr1.symbol, &ptr1);

    return 0;
}

Structures can be created inside functions, and such structures can "live" outside the functions (not locally) if the function returns a pointer to such a structure:

main


              1234567891011121314151617181920212223242526272829303132
            
#include <stdio.h>
#include <stdlib.h>

// structure definition
typedef struct {
    int value;
}Example;

// function creates a structure with the given field
Example* CreateStruct(int setVal)
{
    Example* ptr = (Example*)malloc(sizeof(Example));

    // check for successful memory allocation
    if (ptr != NULL)
    {
        ptr->value = setVal;
        return ptr;
    }
}

int main() 
{
    // use function to create structure 
    Example* ptrToStruct = CreateStruct(23);

    printf("Value inside struct: %d", ptrToStruct->value);

    free(ptrToStruct); // free memory

    return 0;
}

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Все було зрозуміло?

Секція 2. Розділ 5

Passing Structs to the Functions

Functions can work with structures just like with regular variables:

main


              123456789101112131415161718192021
            
#include <stdio.h>

// structure definition
typedef struct {
    char name[50];
} Person;

// function to display information about a person
void printPerson(Person p) {
    printf("Name: %s\n", p.name);
}

int main() {
    // creating a structure and initializing its values
    Person person1 = {"John"};

    // call a function to display information about a person
    printPerson(person1);

    return 0;
}

In order for a function to "interact" with a structure, for example, change the fields of an existing structure, the function must accept a pointer to the structure:

main


              12345678910111213141516171819202122232425262728293031
            
#include <stdio.h>

// structure definition
Typedef struct {
    char symbol;
}Example;

// function for changing the values of structure fields via a pointer
void changePoint(Example* ptr, int newSymbol)
{
    // check for NULL pointer
    if (ptr != NULL)
    {
        ptr->symbol = newSymbol;
    }
}

int main() {
    // create the Example structure and a pointer
    Example ptr1 = {'H'};
    Example* ptr = &ptr1;

    printf("Old symbol: %c | %p\n", ptr1.symbol, &ptr1);

    // use function to change the field of structures
    changePoint(ptr, 'y');

    printf("New symbol: %c | %p\n", ptr1.symbol, &ptr1);

    return 0;
}

Structures can be created inside functions, and such structures can "live" outside the functions (not locally) if the function returns a pointer to such a structure:

main


              1234567891011121314151617181920212223242526272829303132
            
#include <stdio.h>
#include <stdlib.h>

// structure definition
typedef struct {
    int value;
}Example;

// function creates a structure with the given field
Example* CreateStruct(int setVal)
{
    Example* ptr = (Example*)malloc(sizeof(Example));

    // check for successful memory allocation
    if (ptr != NULL)
    {
        ptr->value = setVal;
        return ptr;
    }
}

int main() 
{
    // use function to create structure 
    Example* ptrToStruct = CreateStruct(23);

    printf("Value inside struct: %d", ptrToStruct->value);

    free(ptrToStruct); // free memory

    return 0;
}

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Все було зрозуміло?

Functions can work with structures just like with regular variables:

main


              123456789101112131415161718192021
            
#include <stdio.h>

// structure definition
typedef struct {
    char name[50];
} Person;

// function to display information about a person
void printPerson(Person p) {
    printf("Name: %s\n", p.name);
}

int main() {
    // creating a structure and initializing its values
    Person person1 = {"John"};

    // call a function to display information about a person
    printPerson(person1);

    return 0;
}

In order for a function to "interact" with a structure, for example, change the fields of an existing structure, the function must accept a pointer to the structure:

main


              12345678910111213141516171819202122232425262728293031
            
#include <stdio.h>

// structure definition
Typedef struct {
    char symbol;
}Example;

// function for changing the values of structure fields via a pointer
void changePoint(Example* ptr, int newSymbol)
{
    // check for NULL pointer
    if (ptr != NULL)
    {
        ptr->symbol = newSymbol;
    }
}

int main() {
    // create the Example structure and a pointer
    Example ptr1 = {'H'};
    Example* ptr = &ptr1;

    printf("Old symbol: %c | %p\n", ptr1.symbol, &ptr1);

    // use function to change the field of structures
    changePoint(ptr, 'y');

    printf("New symbol: %c | %p\n", ptr1.symbol, &ptr1);

    return 0;
}

Structures can be created inside functions, and such structures can "live" outside the functions (not locally) if the function returns a pointer to such a structure:

main


              1234567891011121314151617181920212223242526272829303132
            
#include <stdio.h>
#include <stdlib.h>

// structure definition
typedef struct {
    int value;
}Example;

// function creates a structure with the given field
Example* CreateStruct(int setVal)
{
    Example* ptr = (Example*)malloc(sizeof(Example));

    // check for successful memory allocation
    if (ptr != NULL)
    {
        ptr->value = setVal;
        return ptr;
    }
}

int main() 
{
    // use function to create structure 
    Example* ptrToStruct = CreateStruct(23);

    printf("Value inside struct: %d", ptrToStruct->value);

    free(ptrToStruct); // free memory

    return 0;
}

Завдання

Provide the correct return type and args of the function
Inside function create a pointer variable and allocate memory for your structure;
Сreate a pointer to store the address returned by the function;
Displaying the info about your person;
Free up the allocated memory.

Секція 2. Розділ 5