Error when assigning variable value to vector in C

Question

I am creating a user register using struct. In it, there’s the CPF field. As it is a very large field to store in number format, I decided to save as a string, as well as in a database where Cpf is saved with varchar.

I do a validation to not allow registering 2 equal numbers. For this, first I save the value in an auxiliary variable and passing the validation I saved in the vector. The problem is when I pass the value of the variable to the vector.

Error on the line where I pass the value of the variable to the vector: vet[i].cpf = cpfAux;

[Error] assignment to Expression with array type

My code:

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

struct colaborador{
    char nome[50];
    char cpf[18];
    char nascimento[11];
    float salario;
};

struct colaborador vet[2];
int i, j;
char nomePesquisa[30];
char cpfAux[18];
int contPesquisa = 0;
bool rep = false;

int cadastra(){


    for(i=0; i<2; i++){ 
        printf("Insira o nome:");
        gets(vet[i].nome);

        printf("Insira o cpf:");
        gets(cpfAux);


            for(j=0; j<2; j++){
                while(strcmp(cpfAux,vet[j].cpf) == 0) {
                    rep = true;
                    printf("ERRO, CPFS IGUAIS!\n\n");

                    printf("Insira o cpf novamente:");
                    gets(cpfAux);                   
                } 

                rep = false;
            }       

            if(rep == false){
                vet[i].cpf = cpfAux;
            }           



        printf("Insira o nascimento:");
        gets(vet[i].nascimento);


        printf("Insira o salario:");
        scanf("%f", &vet[i].salario);               
        fflush(stdin);
    }

}

int pesquisa(){

    printf("Insira um colaborador a ser pesquisado:");
    scanf("%s", &nomePesquisa);

    for(i=0; i<2; i++){     
        if(strcmp(nomePesquisa,vet[i].nome) == 0){
            printf("Nome: %s\n", vet[i].nome);
            printf("CPF: %s\n", vet[i].cpf);
            printf("Nascimento: %s\n", vet[i].nascimento);
            printf("Salario: %2.f\n", vet[i].salario);
            exit(0);
        } else {
            contPesquisa++;
        }
    }

    if(contPesquisa > 0){
        printf("Colaborador nao encontrado.");
    }

}


int main(int argc, char *argv[]) {

    cadastra(); 
    pesquisa(); 

    return 0;
}

I tested the code using int for Cpf and it worked. The problem is when I put 10-12-15 digits. I tried using the type double, but when the first character is zero-0, it does not store.

How can I fix this? Where am I going wrong?

Answer 1

Instead of:

vet[i].cpf = cpfAux;

You must use:

strcpy(vet[i].cpf, cpfAux);

This method copies the value of cpfAux and assigns it to the vet[i].cpf.

Answer 2

In C, it is not possible to copy the contents of buffers containing strings ended in \0 (array types) using the allocation operator =.

The header pattern string.h provides a complete interface for string handling.

This interface has a function called strcpy(), capable of copying the contents of a buffer to another.

To solve your problem, first, you must include the header string.h in your program:

#include <string.h>

Then replace the line where the error occurs with:

strcpy( vet[i].cpf, cpfAux );