What is HashSet in Java

In Java, HashSet is a similar arrangement that only accepts the unique value. Outputs only once if there are multiple equal value values.

🌱Sample

import java.util.HashSet;

public class Test {

    public static void main(String[] args) {

        HashSet<String> codes = new HashSet<String>();
        codes.add("apple");
        codes.add("pear");
        codes.add("grapes");
        codes.add("mango");
        codes.add("grapes");
        System.out.println(codes); // result: [grapes, mango, pear, apple]
    }
}

🌱Delete , Clear Sample

import java.util.HashSet;

public class Test {

    public static void main(String[] args) {

        HashSet<String> codes = new HashSet<String>();
        codes.add("apple");
        codes.add("pear");
        codes.add("grapes");
        codes.add("mango");
        codes.add("grapes");
        codes.remove("apple");
        System.out.println(codes); // result: [grapes, mango, pear]
        codes.clear();
        System.out.println(codes); // result: []
    }
}

🌱Sample element presence check

import java.util.HashSet;

public class Test {

    public static void main(String[] args) {

        HashSet<String> codes = new HashSet<String>();
        codes.add("apple");
        codes.add("pear");
        codes.add("grapes");
        codes.add("mango");
        codes.add("grapes");
        System.out.println(codes.contains("mango")); // result: true
    }
}

🌱HashSet’s for_each Repeated Statement

import java.util.HashSet;

public class Test {

    public static void main(String[] args) {

        HashSet<String> codes = new HashSet<String>();
        codes.add("apple");
        codes.add("pear");
        codes.add("grapes");
        codes.add("mango");
        codes.add("grapes");
        for (String i : codes) {
            System.out.println(i);
        }

    }
}

// result : grapes, mango, pear, apple

🌱Specifying data types other than String

import java.util.HashSet;

public class Test {

    public static void main(String[] args) {

        HashSet<Integer> nums = new HashSet<Integer>();
        nums.add(3);
        nums.add(5);
        nums.add(2);
        System.out.println(nums); // result: [2, 5, 3]

    }
}