JAVA EE: Java : Collection Framework : TreeMap (SubMap Inclusive)

Thursday 5 February 2015

Java : Collection Framework : TreeMap (SubMap Inclusive)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=HVTWGM9B2jw&list=UUhwKlOVR041tngjerWxVccw

TreeMapExample.java

import java.util.NavigableMap;
import java.util.TreeMap;

/*
 * Example of subMap(K fromKey,
                     boolean fromInclusive,
                     K toKey,
                     boolean toInclusive) method.
 */
public class TreeMapExample
{
    public static void main( String[] args )
    {

        TreeMap<Integer, String> treeMap = new TreeMap<Integer, String>();

        treeMap.put(10, "Cat");
        treeMap.put(50, "Dog");
        treeMap.put(30, "Apple");
        treeMap.put(40, "Ball");
        treeMap.put(20, "Eagle");

        System.out.println("treeMap : " + treeMap + "\n");

        /*
         * Returns a view of the portion of this map whose keys range from
         * fromKey to toKey. If fromKey and toKey are equal, the returned map is
         * empty unless fromInclusive and toInclusive are both true. The
         * returned map is backed by this map, so changes in the returned map
         * are reflected in this map, and vice-versa. The returned map supports
         * all optional map operations that this map supports.
         */
        NavigableMap<Integer, String> navigableMap = treeMap.subMap(10, false,
                40, false);

        System.out
                .println("navigableMap [fromInclusive and toInclusive are both false] : "
                        + navigableMap + "\n");
        
        navigableMap = treeMap.subMap(10, true,
                40, true);

        System.out
                .println("navigableMap [fromInclusive and toInclusive are both true] : "
                        + navigableMap + "\n");

    }
}

Output

treeMap : {10=Cat, 20=Eagle, 30=Apple, 40=Ball, 50=Dog}

navigableMap [fromInclusive and toInclusive are both false] : {20=Eagle, 30=Apple}

navigableMap [fromInclusive and toInclusive are both true] : {10=Cat, 20=Eagle, 30=Apple, 40=Ball}