Aprende Passing Structs to the Functions

Functions can work with structures just like with regular variables:

main.c


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#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.c


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#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.c


              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;
}

Tarea

Swipe to start coding

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.

Solución

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Sección 2. Capítulo 5

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Functions can work with structures just like with regular variables:

main.c


              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.c


              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.c


              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;
}

Tarea

Swipe to start coding

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.

Solución

Cambia al escritorio para practicar en el mundo realContinúe desde donde se encuentra utilizando una de las siguientes opciones

¿Todo estuvo claro?

¡Gracias por tus comentarios!

Sección 2. Capítulo 5

single

Passing Structs to the Functions

Solución

Awesome!

Passing Structs to the Functions

Solución

Awesome!