There are lots of problem with your code:
Given the longest word in English is around 30 characters, this size allocation is realistic for the word, but not for the defintion:
newword.name = (char*)malloc(30*sizeof(char));
newword.mean = (char*)malloc(30*sizeof(char));
This makes little obvious sense:
dic.size = 0;
dic.word = (Words*)malloc(dic.size*sizeof(Words));
you called malloc() on zero! You're only spared by your later realloc(). Even if intentional, it really deserves a comment.
This doesn't really work as fflush() is for output streams:
fflush(stdin);
see: How to clear input buffer in C? And whatever fix you use has to apply to both scanf() calls, not just one!
Per @Jarvis, this doesn't work:
dic.word = (Words*)realloc(dic.word,dic.size*sizeof(Words));
strcpy(dic.word[dic.size-1].name, newword.name);
strcpy(dic.word[dic.size-1].mean, newword.mean);
as you didn't allocate any space for name and mean in dic so you're copying into random memory.
Per @Jarvis, doesn't work:
void addNewWord(Words newword, Dictionary dic){
dic.size++;
dic.word = (Words*)realloc(dic.word,dic.size*sizeof(Words));
You're passing dic by value so inside addnewWord() you've a copy of dic so the original dic's size will be the same as it was before the call!
Memory leak:
addNewWord(createNewWord(), d);
you dropped your handle onto what createNewWord() returned so you can never free the memory it malloc()'d
You malloc() memory but provide no means to eventually free it.
Passing and returning structs by value is a disaster in a situation like this, as the data keeps getting copied. At the least it's inefficient, at worst its buggy like the size issue above. Rather than risk it, pretend they can only be passed and returned by pointer and you'll be playing it safe and get a better result.
Below is a rework of your code (in C) with fixes, style tweaks and an attempt at a consistent terminology. It also provides some minimal test code and the ability to free your data:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_WORD_LENGTH 30
#define MAX_DEFINITION_LENGTH 1024
typedef struct entry {
char *word;
char *definition;
} Entry;
typedef struct dictionary {
Entry *entries;
int num_entries, max_entries;
} Dictionary;
Dictionary *createNewDictionary() {
Dictionary *dictionary = malloc(sizeof(*dictionary));
dictionary->num_entries = 0;
dictionary->max_entries = 1;
dictionary->entries = calloc(dictionary->max_entries, sizeof(*dictionary->entries));
return dictionary;
}
void freeEntry(Entry *entry) {
free(entry->word);
free(entry->definition);
free(entry);
}
void freeDictionary(Dictionary *dictionary) {
for (--dictionary->num_entries; dictionary->num_entries >= 0; --dictionary->num_entries) {
// we can't call freeWord() here -- why.
free(dictionary->entries[dictionary->num_entries].word);
free(dictionary->entries[dictionary->num_entries].definition);
}
free(dictionary->entries);
free(dictionary);
}
void purgeInput() {
int c;
while ((c = getchar()) != '\n' && c != EOF) { }
}
Entry *requestNewEntry() {
Entry *entry = malloc(sizeof(*entry));
entry->word = malloc(MAX_WORD_LENGTH);
entry->definition = malloc(MAX_DEFINITION_LENGTH);
printf("============================\n");
printf("Enter word: ");
scanf("%[^\n]", entry->word);
purgeInput();
printf("\nEnter definition: ");
scanf("%[^\n]", entry->definition);
purgeInput();
return entry;
}
void addNewEntry(Entry *entry, Dictionary *dictionary) {
if (dictionary->num_entries == dictionary->max_entries) {
dictionary->max_entries *= 2;
dictionary->entries = realloc(dictionary->entries, dictionary->max_entries * sizeof(*dictionary->entries));
// check if realloc returns NULL and if so, handle the error.
}
dictionary->entries[dictionary->num_entries].word = strdup(entry->word);
dictionary->entries[dictionary->num_entries].definition = strdup(entry->definition);
dictionary->num_entries++;
}
int main() {
Dictionary *d = createNewDictionary();
for (int i = 0; i < 3; i++) {
Entry *e = requestNewEntry();
addNewEntry(e, d);
freeEntry(e);
}
printf("\nRead: ");
for (int i = 0; i < d->num_entries; i++) {
printf("%s (%lu chars) ", d->entries[i].word, strlen(d->entries[i].definition));
}
printf("\n");
freeDictionary(d);
return 0;
}
CREATING A PUN DICTIONARY
> ./a.out
============================
Enter word: silkworm
Enter definition: Two silkworms had a race but ended up in a tie.
============================
Enter word: horse
Enter definition: A horse is a stable animal.
============================
Enter word: termite
Enter definition: A termite walks into a pub and asks, "Is the bar tender here?"
Read: silkworm (47 chars) horse (27 chars) termite (62 chars)
>
