Difference between HashMap, LinkedHashMap and TreeMap

Question

What is the difference between HashMap, LinkedHashMap and TreeMap in Java? I don\'t see any difference in the output as all the three

Answer 1

HashMap

• It has pair values(keys,values)
• NO duplication key values
• unordered unsorted
• it allows one null key and more than one null values

HashTable

• same as hash map
• it does not allows null keys and null values

LinkedHashMap

• It is ordered version of map implementation
• Based on linked list and hashing data structures

TreeMap

• Ordered and sortered version
• based on hashing data structures