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Program: How to get subset from sorted set?
Description: |
To implement your own sorting functionality with TreeSet on user defined objects, you
have to pass Comparator object along with TreeSet constructor call. The Comparator implementation holds the sorting logic. You have to override compare()
method to provide the sorting logic on user defined objects. Now you can get range of object from the treeset by calling
subSet() method.
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Code: |
package com.java2novice.treeset;
import java.util.Comparator;
import java.util.Set;
import java.util.TreeSet;
public class MySetSublist {
public static void main(String a[]){
TreeSet<String> ts = new TreeSet<String>(new MyStrComp());
ts.add("RED");
ts.add("ORANGE");
ts.add("BLUE");
ts.add("GREEN");
ts.add("WHITE");
ts.add("BROWN");
ts.add("YELLOW");
ts.add("BLACK");
System.out.println(ts);
Set<String> subSet = ts.subSet("GREEN", "WHITE");
System.out.println("sub set: "+subSet);
subSet = ts.subSet("GREEN", true, "WHITE", true);
System.out.println("sub set: "+subSet);
subSet = ts.subSet("GREEN", false, "WHITE", true);
System.out.println("sub set: "+subSet);
}
}
class MyStrComp implements Comparator<String>{
@Override
public int compare(String str1, String str2) {
return str1.compareTo(str2);
}
}
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Output: |
[BLACK, BLUE, BROWN, GREEN, ORANGE, RED, WHITE, YELLOW]
sub set: [GREEN, ORANGE, RED]
sub set: [GREEN, ORANGE, RED, WHITE]
sub set: [ORANGE, RED, WHITE]
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List Of All TreeSet Sample Programs:- Basic TreeSet Operations.
- How to create a TreeSet with a List?
- How to read objects from TreeSet using using Iterator?
- Write a program to remove duplicate entries from an array.
- Write a program to find duplicate value from an array.
- How to create a TreeSet with comparator?
- Create TreeSet with comparator by user define objects.
- How to sort a TreeSet with user defined objects?
- How to get subset from sorted set?
- How to get least value element from a set?
- How to get highest value element from a set?
- How to avoid duplicate user defined objects in TreeSet?
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Class, Constructor and Primitive data types
Class is a template for multiple objects with similar features and it is a blue print for objects. It defines a type of object
according to the data the object can hold and the operations the object can perform. Constructor is a special kind of method that
determines how an object is initialized when created. Primitive data types are 8 types and they are: byte, short, int, long, float,
double, boolean, char.
We know what we are, but know not what we may be.
-- William Shakespeare
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