which interface does hashmap implement in java
package MyPackage;
import java.util.*;
class HashMapExample {
public static void main(String[] args) {
Map< String, Integer> courses = new HashMap< String,Integer>();
// Add some courses.
courses.put("Java Courses", new Integer(6));
courses.put("Cloud Courses", new Integer(7));
courses.put("Programming Courses", new Integer(5));
courses.put("Data Science Courses", new Integer(2));
System.out.println("Total courses: " + courses.size());
Set< Map.Entry< String,Integer> > st = courses.entrySet();
for (Map.Entry< String,Integer> me :st)
{
System.out.print(me.getKey()+":");
System.out.println(me.getValue());
}
System.out.println();
String searchKey = "Java Courses";
if (courses.containsKey(searchKey))
System.out.println("Found total " + courses.get(searchKey) + " " + searchKey);
}
}