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.
To add data to a list in Java, you can follow these steps:
- Create a new instance of the list with the desired data type. For example:
- Use the add() method to add elements to the list. Provide the data you want to add as an argument to the add() method. For example:
ListmyList = new ArrayList<>();
myList.add("Sunflower"); myList.add("Lily"); myList.add("Rose"); myList.add("Marigold");
Example 1: Adding 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 ListmyList = new ArrayList<>(); //Adding string values into list myList.add("Red"); myList.add("Blue"); myList.add("Green"); myList.add("Yellow"); myList.add("Orange"); myList.add("Pink"); myList.add("Purple"); myList.add("White"); myList.add("Black"); //Printing list elements in console System.out.println(myList); } }
The output of the above code is as follows:
[Red, Blue, Green, Yellow, Orange, Pink, Purple, White, Black]
Example 2: Adding 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 integer values ListmyList = new ArrayList<>(); // Adding int values into list myList.add(1); myList.add(2); myList.add(3); myList.add(4); myList.add(5); myList.add(6); myList.add(7); myList.add(8); myList.add(9); //printing list in console System.out.println(myList); } }
The output of the above code is as follows:
[1, 2, 3, 4, 5, 6, 7, 8, 9]
Example 3: Adding 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 integer values ListmyList = new ArrayList<>(); // Adding data of different types into list myList.add("Red"); myList.add(100); myList.add("Green"); myList.add(552); myList.add(true); myList.add(false); myList.add(10.23); //printing list in console System.out.println(myList); } }
The output of the above code is as follows:
[Red, 100, Green, 552, true, false, 10.23]
Example 4: Adding Class Objects to a List in Java
import java.util.ArrayList; import java.util.List; //getter setter class class Student { private int id; private String firstName; private String lastName; public int getId() { return id; } public void setId(int id) { this.id = id; } 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 class ListExample { public static void main(String[] args) { // Creating a new instance of a List List<Student> myList = new ArrayList<>(); // Creating student object 1 Student student1 = new Student(); student1.setId(1); student1.setFirstName("John"); student1.setLastName("A"); //adding first object to the list myList.add(student1); // Creating student object 2 Student student2 = new Student(); student2.setId(2); student2.setFirstName("Jane"); student2.setLastName("B"); //adding second object to the list myList.add(student2); // Iterating using foreach loop myList.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 output of the above code is as follows:
1 John A ------------------------ 2 Jane B ------------------------