How to sort the elements in HashMap
Answers were Sorted based on User's Feedback
Answer / jyoti
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
public class format {
public static void main(String args[]) {
Map<String, Person> people = new
HashMap<String, Person>();
Person jim = new Person("Jim", 25);
Person scott = new Person("Scott", 28);
Person anna = new Person("Anna", 23);
people.put(jim.getName(), jim);
people.put(scott.getName(), scott);
people.put(anna.getName(), anna);
// not yet sorted
ArrayList<Person> peopleByAge = new
ArrayList<Person>(people.values());
Collections.sort(peopleByAge, new
Comparator<Person>()
{
public int compare(Person o1,
Person o2)
{
return o1.getAge() -
o2.getAge();
}
});
for (Person p : peopleByAge) {
System.out.println(p.getName()
+ "\t" + p.getAge());
}
}
}
class Person
{
String name = null;
int age;
Person()
{
}
Person(String name,int age)
{
this.name=name;
this.age=age;
}
public String getName()
{
return this.name;
}
public int getAge()
{
return this.age;
}
}
| Is This Answer Correct ? | 16 Yes | 0 No |
Answer / srinivasa
By implementing comparable interface we can sort the
HashMap
| Is This Answer Correct ? | 11 Yes | 2 No |
Answer / srinivasa
we can use to Collections.syncroniseMap() to synchronize
the HashMap
| Is This Answer Correct ? | 7 Yes | 12 No |
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