examples of set data structure in java

java code to check if a set is a subset from another set or not

import java.util.TreeSet;
import java.util.Set;

class Main {
  public static void main(String[] args) {

    // create the first set
    Set<String> languages = new TreeSet<>();
    languages.add("Java");
    languages.add("JavaScript");
    languages.add("Python");
    languages.add("CSS");
    System.out.println("Programming Languages: " + languages);

    // create the second set
    Set<String> frontend = new TreeSet<>();
    frontend.add("CSS");
    frontend.add("JavaScript");
    System.out.println("Frontend Languages: " + frontend);

    // check if frontend is a subset of languages
    boolean result = languages.containsAll(frontend);
    System.out.println("Is frontend is subset of languages? " + result);
  }
}

java code calculates the difference between 2 sets:

import java.util.HashSet;
import java.util.Set;
import com.google.common.collect.Sets;

class Main {
  public static void main(String[] args) {

    // create the first set
    Set<String> languages1 = new HashSet<>();
    languages1.add("Java");
    languages1.add("JavaScript");
    languages1.add("English");
    languages1.add("Spanish");
    System.out.println("Languages: " + languages1);

    // create second set
    Set<String> languages2 = new HashSet<>();
    languages2.add("English");
    languages2.add("Spanish");
    System.out.println("Human Languages: " + languages2);

    Set<String> intersect = Sets.difference(languages1, languages2);
    System.out.println("Programming Languages: " + intersect);
  }
}

output:

Languages: [Java, JavaScript, English, Spanish]
Human Languages: [English, Spanish]
Programming Languages: [Java, JavaScript]

java code to calculate the intersection between 2 sets:

import java.util.HashSet;
import java.util.Set;
import com.google.common.collect.Sets;

class Main {
  public static void main(String[] args) {

    // create the first set
    Set<String> backend = new HashSet<>();
    backend.add("Java");
    backend.add("JavaScript");
    System.out.println("Backend Languages: " + backend);

    // create second set
    Set<String> frontend = new HashSet<>();
    frontend.add("JavaScript");
    frontend.add("CSS");
    System.out.println("Frontend Languages: " + frontend);

    Set<String> intersect = Sets.intersection(backend, frontend);
    System.out.println("Common Languages: " + intersect);
  }
}

output:

Backend Languages: [Java, JavaScript]
Frontend Languages: [JavaScript, CSS]
Common Languages: [JavaScript]

java program to union on 2 sets , using the set data structure

import java.util.HashSet;
import java.util.Set;
import com.google.common.collect.Sets;

class Main {
  public static void main(String[] args) {

    // create the first set
    Set<String> languages1 = new HashSet<>();
    languages1.add("Java");
    languages1.add("Python");
    System.out.println("Programming Languages: " + languages1);

    // create second set
    Set<String> languages2 = new HashSet<>();
    languages2.add("English");
    languages2.add("Spanish");
    System.out.println("Human Language: " + languages2);

    Set<String> unionSet = Sets.union(languages1, languages2);
    System.out.println("Union is: " + unionSet);
  }
}