[30일코딩] 딕셔너리 Dictionary

Dictionary

1. insert

2. find

3. delete

특징

- key-value pairs

- no-guaranteed order (except Treepmap)

- .size

- boolean? Boolean!

Reference type 사용! primitive type 사용불가!

생성

Map<String, String> engSpanishDic = new HashMap<String, String>

- Map Interface

- concrete class HashMap

Map<String, Boolean> shoppingList = new HashMap<String, Boolean>

shoppingList.put("Ham", true);

shoppingList.put("Icecream", Boolean.FALSE);

사용

// Create a Map of String Keys to String Values, implemented by the HashMap class

Map<String,String> myMap = new HashMap<String,String>(); 

    

// Adds ("Hi","Bye") mapping to myMap

myMap.put("Hi", "Bye");

// Print the Value mapped to from "Hi"

System.out.println(myMap.get("Hi")); 

// Replaces "Bye" mapping from "Hi" with "Bye!" 

myMap.put("Hi", "Bye!"); 

// Print the Value mapped to from "Hi"

System.out.println(myMap.get("Hi"));