linked hashmap code example

Example 1: hashmap vs linkedhashmap

Main difference between HashMap and LinkedHashMap
I remember is that LinkedHashMap maintains
insertion order of keys, 
On the other hand HashMap doesn't maintain
any order or keys or values.
Also LinkedHashMap requires more memory than HashMap
because of the ordering feature.
LinkedHashMap doublly Linked List to 
maintain order of elements.

Example 2: linkedhashmap in java

LinkedHashMap is same as HasHMap just additionally maintains the insertion order.

Example 3: linked hashmap

LinkedHashMap can have null key, keeps order