What is the use of Hashmap in java??

Question

Hashmap

Answer 1

In a HashMap you can store data collections. You store a pair (key, value).
For example you want a list of persons and their jobs.
Person --> key
Job --> value
"John Doe"; "Teacher"
"Jane Doe"; "Programmer"
...
Hashmap: [John Doe = Teacher, Jane Doe = Programmer]
The special thing is that you can not use a key more than one time. Adding a key that already exists, overwrites the old element.

In the challenge adjacent clone letters I used a Hashmap for the letters (key) and the number of clones (values). Because I wanted the connection between the letter and their clones. And I didn't want duplicates.

https://code.sololearn.com/cy5oNTefTXIb/?ref=app

Answer 2

Thank you

Answer 3

You can also look here: https://www.sololearn.com/learn/Java/2181/?ref=app

Answer 4

How do you format it correctly? I've been searching for this function similar to a dictionary in python. Can you assign the same name to a key and value such as
"Apple"; "Apple" ?