how to create a hashmap in java

1Map<String, String> myMap = new HashMap<String, String>() {{
2        put("a", "b");
3        put("c", "d");
4    }};

1// Import the HashMap class
2import java.util.HashMap;
3
4	// First Example
5    // Create a HashMap object called capitalCities
6    HashMap<String, String> capitalCities = new HashMap<String, String>();
7
8    // Add keys and values (Country, City)
9    	capitalCities.put("England", "London");
10    	capitalCities.put("Germany", "Berlin");
11    	capitalCities.put("Norway", "Oslo");
12    	capitalCities.put("USA", "Washington DC");
13    	System.out.println(capitalCities);
14
15	//Second Example
16	// Create a HashMap object called stGrade
17	Map<String, Integer> stGrade = new HashMap<String, Integer>(); 
18
19	// Insert elements 
20       	stGrade.put("aaron", new Integer(90)); 
21       	stGrade.put("isaac", new Integer(100)); 
22       	stGrade.put("john", new Integer(35)); 
23       	stGrade.put("mohammad", new Integer(100)); 
24
25	// Get value
26	   	stGrade.get("mohammad"); 	// returns 100
27		stGrade.get("aaron"); 		// returns 90
28		stGrade.get("john");	 	// returns 35
29		stGrade.get("isaac"); 		// returns 100
30		

1//remember to first import java.util.*; first
2
3//you can swap out string or integer for other data types
4Map<String, Integer> d = new HashMap<>();
5

1//Hash map creation
2Map< String,Integer> hm =  
3                        new HashMap< String,Integer>(); 
4//inserting elements into hashmap
5       hm.put("a", new Integer(100)); 
6       hm.put("b", new Integer(200)); 
7       hm.put("c", new Integer(300)); 
8       hm.put("d", new Integer(400)); 

1   HashMap<Integer,String> map=new HashMap<Integer,String>();//Creating HashMap    
2

1HashMap<Integer,String> map=new HashMap<Integer,String>();//key is integer, value is String