How to Add Data to a List in Java

A List is a data structure that allows to store collections of data in a single object.

Adding String values to a List in Java

The example below demonstrates how to add string values to a list in Java:

import java.util.ArrayList;
import java.util.List;

public class ListExample {

	public static void main(String [] args) {
		
		//creating a list object for storing string values
		List<String> list = new ArrayList<>();

        //inserting string values into list
		list.add("Red");
		list.add("Blue");
		list.add("Green");
		list.add("Yellow");
		list.add("Orange");
		list.add("Pink");
		list.add("Purple");
		list.add("White");
		list.add("Black");
		
		//printing list in console
		System.out.println(list);
	}
}    

The above code gives the following output:

Adding Integer values to a List in Java

The example below demonstrates how to add integer values to a list in Java:

import java.util.ArrayList;
import java.util.List;

public class ListExample {

	public static void main(String [] args) {
		
		//creating a list object for storing intter values
		List<Integer> list = new ArrayList<>();

        //inserting int values into list
		list.add(1);
		list.add(2);
		list.add(3);
		list.add(4);
		list.add(5);
		list.add(6);
		list.add(7);
		list.add(8);
		list.add(9);
		
		//printing list in console
		System.out.println(list);
	}
}

The above code gives the following output:

Adding values of Different Data Types to a List in Java

The example below demonstrates how to add values of different data types to a list in Java:

import java.util.ArrayList;
import java.util.List;

public class ListExample {

	public static void main(String [] args) {
		
		//creating a list object for storing data of different data types
		List<Object> list = new ArrayList<>();

        //inserting data of different types into list
		list.add("Red");
		list.add(1);
		list.add(2);
		list.add("Blue");
		list.add(5);
		list.add(true);
		list.add("Green");
		list.add(10.5);
		list.add(false);
		
		//printing list in console
		System.out.println(list);
	}
}

The above code gives the following output:

Adding Class Objects to a List in Java

The example below demonstrates how to add values of different data types to a list in Java:

import java.util.ArrayList;
import java.util.List;

//getter setter class
class Student {
	private String firstName;
	private String lastName;
	private int id;
	private boolean active;

	public String getFirstName() {
		return firstName;
	}

	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}

	public String getLastName() {
		return lastName;
	}

	public void setLastName(String lastName) {
		this.lastName = lastName;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public boolean isActive() {
		return active;
	}

	public void setActive(boolean active) {
		this.active = active;
	}

}

public class ListExample {

	public static void main(String[] args) {

		// Creating a list object for storing objects of Student class
		List<Student> list = new ArrayList<>();
		
		//Creating student object 1
		Student student1 = new Student();
		student1.setFirstName("John");
		student1.setLastName("A");
		student1.setId(1);
		student1.setActive(false);
		
		//adding first object to list
		list.add(student1);
		
		//Creating student object 2
		Student student2 = new Student();
		student2.setFirstName("Rose");
		student2.setLastName("B");
		student2.setId(2);
		student2.setActive(true);
		
		//adding second object to list
		list.add(student2);
		
		//Creating student object 3
		Student student3 = new Student();
		student3.setFirstName("Jasmine");
		student3.setLastName("C");
		student3.setId(3);
		student3.setActive(true);
		
		//adding third object to list
		list.add(student3);
		
		//Creating student object 4
		Student student4 = new Student();
		student4.setFirstName("April");
		student4.setLastName("D");
		student4.setId(4);
		student4.setActive(false);
		
		//adding fourth object to list
		list.add(student4);

		list.forEach(student -> {
			System.out.println(student.getFirstName());
			System.out.println(student.getLastName());
			System.out.println(student.getId());
			System.out.println(student.isActive());
			System.out.println("------------------------");
		});
	}
}

The above code gives the following output: