What is LinkedHashMap and what is it used for?
When I looked at the sample code containing the ListView, I thought of LinkedHashMap
.
What is LinkedHashMap
, where and how can we use it? I went through several articles and didn’t fully understand. Whether it is required when creating a ListView
. What is the connection between ListViews and LinkedHashMaps? Thank you.
Solution
For simplicity, let’s understand the difference between HashMap and LinkedHashMap.
HashMap: It provides output in random order, which means we insert values in the wrong order.
Whereas
LinkedHashMap: It gives output in order.
Let’s look at a small example: using HashMap
// suppose we have written a program
.
.
now use HashMap
HashMap map = new HashMap(); create object
map.put(1,"Rohit"); insert values
map.put(2,"Rahul");
map.put(3,"Ajay");
System.out.println("MAP=" +map); print the output using concatenation
So the output may be in any order like we can say the output may be as:
Map={3=Ajay,2=Rahul,1=Rohit}
But that’s not the case in LinkedHashMap
Just replace “HashMap” with “LinkedHashMap” in the code above
Look
It will display the outputs sequentially, e.g. 1=Rohit will display first, and then the other outputs in order.