Field in Java 20

In Java, a field is a variable that belongs to a class or an object. It stores the data that can be accessed and modified by the code in the class. Here are some examples of how to use fields in a Java class:

1. Declaring a field in a class:

public class Person {
  String name;
  int age;
}

In this example, the Person class has two fields: name of type String and age of type int.

2. Initializing a field with a value:

public class Student {
  String name = "John Smith";
  int age = 18;
}

In this example, the Student class has two fields name and age that are initialized with default values.

3. Accessing and modifying a field:

public class Car {
  String color;
  
  public void setColor(String newColor) {
    color = newColor;
  }
  
  public String getColor() {
    return color;
  }
}
// Main program

Car mycar = new Car();

mycar.setColor("red");

System.out.println(mycar.getColor());

In this example, the Car class has a field color, which can be set and retrieved using the methods setColor() and getColor(). The mycar object is created and its color is set to "red" using the setColor() method. Then, the getColor() method is called and the output is "red".

Fields are an essential part of Java classes as they allow us to store and retrieve data within objects.