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:
[Red, Blue, Green, Yellow, Orange, Pink, Purple, White, Black]
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:
[1, 2, 3, 4, 5, 6, 7, 8, 9]
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:
[Red, 1, 2, Blue, 5, true, Green, 10.5, false]
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:
John
A
1
false
------------------------
Rose
B
2
true
------------------------
Jasmine
C
3
true
------------------------
April
D
4
false
------------------------
A
1
false
------------------------
Rose
B
2
true
------------------------
Jasmine
C
3
true
------------------------
April
D
4
false
------------------------