A Hash Table implementation in C.

gcc src/ht/*.c src/main.c -o main && ./main

Output:

A Hash Table implementation in C

k1: value 1
k2: value 2
k3: value 3

Not present key: (null)
Not present key with default: default

Removed key: (null)
Removed key with default: default

Include the header:

#include "ht/hash_table.h"

Create a hash table:

HashTable *ht = HashTable_new();

Remember to delete the hash table to free the memory:

HashTable_delete(ht);

Insert an item:

HashTable_insert(ht, "key", "value");

Get the value:

char *v = HashTable_get(ht, "key"); // returns NULL if key not present

Get the value with default:

char *v = HashTable_get_default(ht, "key", "default"); // returns "default" if key not present

Remove an item:

HashTable_remove(ht, "key");

HashTable will automatically resize based upon load (<0.1 to resize down with a minimum size of 50, >0.7 to resize up).

However, you may create a sized table directly if you know how many items you'll be storing beforehand with:

// Creates a hash table with base size 100 (actual size will be a prime number >= 100)
HashTable *ht = HashTable_new_sized(100);

You may also manually resize the table up / down by:

// Resize to roughly double the current size
HashTable_resize_up(ht);

// Resize to roughly half the current size (unless size is already minimum)
HashTable_resize_down(ht);

All contributions are welcome. Please create an issue first for any feature request or bug. Then fork the repository, create a branch and make any changes to fix the bug or add the feature and create a pull request. That's it! Thanks!

Hash Table is released under the MIT License. Check out the full license here.