CODEWITHSUNDEEP
carraysstringdynamic
Muhammad Haryadi Futra
Muhammad Haryadi Futra

Reputation: 421

How do I make a struct containing a dynamic array of strings in C?

I have three files: header.h, machine.c, and main.c

  1. How do I create a struct containing a dynamic array of strings?
  2. How do I fill the strings using functions in machine.c?
  3. How do I print that dynamic array of string?

My header.h file:

typedef struct smp * alamat; 
typedef struct smp{
int jd;
int level;
char c[100];
char * words;   
alamat sibling;
alamat child;
}simpul;

I want to add a dynamic array of strings into variable words in that struct. My machine.c file looks like this:

 void addChild(char c[], char *dosa, int n, simpul* s){
    int i;
    if(s != NULL){//simpul tidak kosong
        dosa = malloc(n * sizeof(char*));
        simpul* baru = (simpul*)malloc(sizeof(simpul));
        strcpy(baru->c,c);
        baru-> jd = n;
        baru->words = dosa;

        if(s->child == NULL){//tidak punya anak
            baru->child = NULL;
            baru->sibling = NULL;
            s->child = baru;
        }else if(s->child->sibling == NULL){//anak cuma 1
            baru->child = NULL;
            s->child->sibling = baru;
            baru->sibling = s->child;
        }else{//anak banyak
            simpul * terakhir = s->child;
            while(terakhir->sibling != s->child){
                terakhir = terakhir->sibling;
            }
            terakhir ->sibling = baru;
            baru->child = NULL;
            baru->sibling = s->child;
        }
    }       
}

My main is like this to pass the array of string to the machine.c:

impul * node = findSimpul(penanda,t.root);

        char *string = (char *) malloc( (n* sizeof(char)));
        for(k=0;k<n;k++){
            scanf("%s",&string[k]);
        }
        addChild(anak,string,n,node);

How do I solve these problems?

Upvotes: 1

Views: 538

Answers (1)

Jan Matejka
Jan Matejka

Reputation: 1970

You need an array of pointers.

char **strings;

int nmemb = 1;
strings = calloc(nmemb, sizeof(*char));
strings[0] = calloc(your_str_len, sizeof(char));

// now you have allocated space for one string. in strings[0]

// let's add another
nmemb = 2;
strings = realloc(strings, sizeof(*char) * nmemb);
strings[1] = calloc(your_2nd_str_len, sizeof(char));
// now you are ready to use the second string in string[1]

Upvotes: 2

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