how to use a hashmap in java code example

Example 1: new hashmap java

Map<String, String> myMap = new HashMap<String, String>() {{
        put("a", "b");
        put("c", "d");
    }};

Example 2: declare hashmap java

//remember to first import java.util.*; first

//you can swap out string or integer for other data types
Map<String, Integer> d = new HashMap<>();

Example 3: hashmaps java

import java.util.HashMap;
//Within a class
//You can do new HashMap<Key Type, Value Type>();, but you don't need to
HashMap<Int, String> examplehashmap=new HashMap<>();
{
//put in values
 examplehashmap.put(5, "example");
};
//get value
examplehashmap.get(5);
//returns "example"

Example 4: how to create a hashmap in java

HashMap<Integer,String> map=new HashMap<Integer,String>();//key is integer, value is String