RetroSearch Browse

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://www.geeksforgeeks.org/java/vector-contains-method-in-java/ below:

Java Vector contains() Method - GeeksforGeeks

Java Vector contains() Method

Last Updated : 16 Jan, 2025

The contains() method in Java is used to check whether a specific element is present in the Vector or not.

Example 1: In this example, we will check whether a particular string is present in the vector or not.

Java


 // Java program to demonstrate the use 
// of the contains() method with Strings
import java.util.Vector;

public class Geeks {
    public static void main(String[] args) {
      
        // Create a vector to store strings
        Vector<String> v = new Vector<>();

        // Add elements to the vector
        v.add("Welcome");
        v.add("To");
        v.add("Geeks");
        v.add("4");
        v.add("Geeks");

        // Display the contents of the vector
        System.out.println("Vector: " + v);

        // Check if the vector contains "Geeks"
        System.out.println("Contains 'Geeks'? " 
                           + v.contains("Geeks")); 

        // Check if the vector contains "4"
        System.out.println("Contains '4'? " 
                           + v.contains("4"));         

        // Check if the vector contains "No"
        System.out.println("Contains 'No'? " 
                           + v.contains("No"));      
    }
}

Output

Vector: [Welcome, To, Geeks, 4, Geeks]
Contains 'Geeks'? true
Contains '4'? true
Contains 'No'? false

Syntax of Vector contains() Method

boolean contains(Object obj)

Parameters: obj: The element to be checked for its presence in vector.

Return Type:

It returns true, if the element is present in the vector
It returns false, if the element is not present in the vector

Example 2: In this example, we will check whether a particular integer element is present in the vector or not.

Java


 // Java program to demonstrate the use 
// of the contains() method with Integers
import java.util.Vector;

public class Geeks {
    public static void main(String[] args) {
      
        // Create a vector to store integers
        Vector<Integer> v = new Vector<>();

        // Add elements to the vector
        v.add(10);
        v.add(15);
        v.add(30);
        v.add(20);
        v.add(5);

        // Display the contents of the vector
        System.out.println("Vector: " + v);

        // Check if the vector contains 100
        System.out.println("Contains 100? " 
                           + v.contains(100)); 

        // Check if the vector contains 30
        System.out.println("Contains 30? " 
                           + v.contains(30));   
    }
}

Output

Vector: [10, 15, 30, 20, 5]
Contains 100? false
Contains 30? true

Example 3: The below Java program demonstrates how the contains() method works with custom objects by overriding the equals() method.

Java


 // Java program to demonstrate the 
// contains() method with custom objects
import java.util.Vector;

class Person {
    String name;
    int age;

    // Constructor to initialize Person objects
    Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    // Overriding equals() to compare custom objects
    @Override
    public boolean equals(Object obj) {
      
         // Check if the same object is compared
        if (this == obj) 
          return true;
        if (obj == null || getClass() != obj.getClass())
          
          // Check for null or different types
          return false; 
        Person person = (Person) obj;
        return age == person.age && name.equals(person.name); 
    }

    // Overriding toString() for 
    // better output readability
    @Override
    public String toString() {
        return "Person{name='" + name + "', age=" + age + "}";
    }
}

public class Main {
    public static void main(String[] args) {
      
        // Create a vector to store custom Person objects
        Vector<Person> v = new Vector<>();

        // Add Person objects to the vector
        v.add(new Person("Geek1", 25));
        v.add(new Person("Geek2", 30));
        v.add(new Person("Geek3", 35));

        // Display the contents of the vector
        System.out.println("Vector: " + v);

        // Check if the vector contains 
        // a specific Person object
        System.out.println("Contains Geek1? " + 
                           v.contains(new Person("Geek1", 25))); 

        // Check if the vector contains 
        // another specific Person object
        System.out.println("Contains Geek5? " 
                           + v.contains(new Person("Geek5", 40))); 
    }
}

Output

Vector: [Person{name='Geek1', age=25}, Person{name='Geek2', age=30}, Person{name='Geek3', age=35}]
Contains Geek1? true
Contains Geek5? false

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4