Java LinkedHashSet contains() Method

The LinkedHashSet.contains() method in Java is used to check if a particular element is present in a LinkedHashSet.

Table of Contents

1. Introduction
2. contains Method Syntax
3. Examples
   • Checking for Elements in a LinkedHashSet
   • Handling Elements Not in the LinkedHashSet
4. Conclusion

Introduction

The LinkedHashSet.contains() method is a member of the LinkedHashSet class in Java. It allows you to check if a specific element is present in the LinkedHashSet.

contains Method Syntax

The syntax for the contains method is as follows:

public boolean contains(Object o)

• The method takes a single parameter o of type Object, which represents the element to be checked in the LinkedHashSet.
• The method returns a boolean value:
  • true if the element is present in the set.
  • false if the element is not present in the set.

Examples

Checking for Elements in a LinkedHashSet

The contains method can be used to check if specific elements are present in a LinkedHashSet.

Example

import java.util.LinkedHashSet;

public class ContainsExample {
    public static void main(String[] args) {
        // Creating a LinkedHashSet of Strings
        LinkedHashSet<String> animals = new LinkedHashSet<>();

        // Adding elements to the LinkedHashSet
        animals.add("Lion");
        animals.add("Tiger");
        animals.add("Elephant");

        // Checking if certain elements are present in the LinkedHashSet
        boolean containsLion = animals.contains("Lion");
        boolean containsMonkey = animals.contains("Monkey");

        // Printing the results
        System.out.println("Contains Lion: " + containsLion);
        System.out.println("Contains Monkey: " + containsMonkey);
    }
}

Output:

Contains Lion: true
Contains Monkey: false

Handling Elements Not in the LinkedHashSet

The contains method returns false if the element is not present in the LinkedHashSet.

Example

import java.util.LinkedHashSet;

public class NotContainsExample {
    public static void main(String[] args) {
        // Creating a LinkedHashSet of Strings
        LinkedHashSet<String> animals = new LinkedHashSet<>();

        // Adding elements to the LinkedHashSet
        animals.add("Lion");
        animals.add("Tiger");
        animals.add("Elephant");

        // Checking if an element that is not in the LinkedHashSet
        boolean containsGiraffe = animals.contains("Giraffe");

        // Printing the result
        System.out.println("Contains Giraffe: " + containsGiraffe);
    }
}

Output:

Contains Giraffe: false

Conclusion

The LinkedHashSet.contains() method in Java provides a way to check if a specific element is present in a LinkedHashSet. By understanding how to use this method, you can efficiently verify the presence of elements in your collections. The method ensures that you can quickly check for the existence of elements, making it useful for various validation and conditional operations in your Java applications.