Important_Notes.txt

** Difference between HashMap and LinkedHashMap :

LinkedHashMap and HashMap are map implementations in Java and their working is almost same.
The main difference between them is that LinkedHashMap maintains the insertion order of the elements (the sequence in which keys are inserted) whereas HashMap does not maintain any order.

Eg : If I am adding a,b,c,d in this order, in my Hashmap and LinkedHashMap,

Then output could be : HashMap (a,c,d,b)
                       LinkedHashMap (a,b,c,d)

LinkedHashMap<String, String> abc = new LinkedHashMap<String, String>();
HashMap<String, String> abc = new HashMap<>();