Answer by Premraj for Difference between HashMap, LinkedHashMap and TreeMap

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