Hashmap Example in Java Example for create instance , put ,get and iterate

Hashmap Example in Java Example for create instance , put ,get and iterate
Hashmap is Collection class in packate java.util
- You can put data to Hashmap with Key and Value
- You can get data from Hashmap with Key
- You can iterate all Key or Value from HashMap

Example Code for Hashmap
package example.util;
import java.util.*;
public class HashmapExample {
public void hashmapExample(){
//Create HashMap Object
HashMap<String,String> hashmap=new HashMap<String,String>();
//Store and Remove data from HashMap
hashmap.put("key1", "value1");
hashmap.put("key2", "value2");
hashmap.put("key3", "value3");
String key3=hashmap.remove("key3");

System.out.println("-- Example for Get Value from HashMap --");
System.out.println("Get Hashmap value: "+hashmap.get("key1"));
System.out.println("Remove Hashmap value: "+key3);
System.out.println("Contains Key Hashmap: "+hashmap.containsKey("key1"));
System.out.println("Contains Key Hashmap: "+hashmap.containsKey("key3"));
System.out.println("Contains Value Hashmap: "+hashmap.containsValue("value1"));
System.out.println("Contains Value Hashmap: "+hashmap.containsValue("value3"));

System.out.println("-- Example for Iterate list from Hash Map --");
Iterator<String> it=hashmap.keySet().iterator();
while(it.hasNext()){
String key=it.next();
String value=hashmap.get(key);
System.out.println("By Key :Key : "+key+"   Value: "+value);
}

it=hashmap.values().iterator();
while(it.hasNext()){
System.out.println("Value "+it.next());
}



}
public static void main (String args[]){
HashmapExample hashmap=new HashmapExample();
hashmap.hashmapExample();
}
}