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:

  • Order not maintains
  • Faster than LinkedHashMap
  • Used for store heap of objects

• LinkedHashMap:

  • LinkedHashMap insertion order will be maintained
  • Slower than HashMap and faster than TreeMap
  • If you want to maintain an insertion order use this.

• TreeMap:

  • TreeMap is a tree-based mapping
  • TreeMap will follow the natural ordering of key
  • Slower than HashMap and LinkedHashMap
  • Use TreeMap when you need to maintain natural(default) ordering