hashmaps java
// Import the HashMap class
import java.util.HashMap;
// Create a HashMap object called capitalCities
HashMap<String, String> capitalCities = new HashMap<String, String>();
// Add keys and values (Country, City)
capitalCities.put("England", "London");
capitalCities.put("Germany", "Berlin");
capitalCities.put("Norway", "Oslo");
capitalCities.put("USA", "Washington DC");
System.out.println(capitalCities);//Hash map creation
Map< String,Integer> hm =
new HashMap< String,Integer>();
//inserting elements into hashmap
hm.put("a", new Integer(100));
hm.put("b", new Integer(200));
hm.put("c", new Integer(300));
hm.put("d", new Integer(400)); import java.util.HashMap; // import the HashMap class
HashMap<String, String> capitalCities = new HashMap<String, String>();
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"// Import the HashMap class
import java.util.HashMap;
// First Example
// Create a HashMap object called capitalCities
HashMap<String, String> capitalCities = new HashMap<String, String>();
// Add keys and values (Country, City)
capitalCities.put("England", "London");
capitalCities.put("Germany", "Berlin");
capitalCities.put("Norway", "Oslo");
capitalCities.put("USA", "Washington DC");
System.out.println(capitalCities);
//Second Example
// Create a HashMap object called stGrade
Map<String, Integer> stGrade = new HashMap<String, Integer>();
// Insert elements
stGrade.put("aaron", new Integer(90));
stGrade.put("isaac", new Integer(100));
stGrade.put("john", new Integer(35));
stGrade.put("mohammad", new Integer(100));
// Get value
stGrade.get("mohammad"); // returns 100
stGrade.get("aaron"); // returns 90
stGrade.get("john"); // returns 35
stGrade.get("isaac"); // returns 100