Java TreeMap:
The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used.
package com.candidjava.core;
import java.util.TreeMap;
public class TreeMapExample {
public static void main(String[] args) {
TreeMap<String,String> tm=new TreeMap<String,String>();
tm.put("name","candid");
tm.put("email","candid@gmail.com");
tm.put("password", "123456");
tm.put("street", "shanthi nagar");
tm.put("password", "789");
tm.put("altemail", null);
tm.put("altph", null);
System.out.println("TreeMap .. "+tm);
System.out.println("size ... "+tm.size());
}
}Output:
TreeMap .. {altemail=null, altph=null, email=candid@gmail.com, name=candid, password=789, street=shanthi nagar}
size ... 6