What is a HashMap?
Part of the Logic & Flow section of Coddy's Java journey — lesson 10 of 59.
A HashMap is a data structure that stores key-value pairs. It allows you to quickly retrieve a value by using its associated key.
Think of it like a dictionary, where each word (key) has a definition (value). HashMap is part of the Java Collections Framework and is widely used for its efficient lookup, insertion, and deletion operations.
HashMaps are useful when you have data that is naturally paired together and when you need to quickly access a value by knowing its associated key.
To use a HashMap in Java, you'll need to import it at the start of your code:
import java.util.HashMap;Cheat sheet
A HashMap is a data structure that stores key-value pairs, allowing quick retrieval of values using their associated keys.
To use a HashMap in Java, import it:
import java.util.HashMap;HashMaps are useful for data that is naturally paired together and when you need efficient lookup, insertion, and deletion operations.
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All lessons in Logic & Flow
1Multi-dimensional Arrays
2D Arrays BasicsAccessing 2D Array ElementsNested Loops with 2D ArraysRecap - 2D ArraysMatrix Addition & SubstractionJagged Arrays3D Arrays And BeyondCommon 2D Array PatternsRecap - All About Arrays2HashMap Part 1
What is a HashMap?Declare a HashMapAccessing ValuesCheck If Key ExistsModifying DictionariesRecap - HashMap