如何在 Java 9 中的 JShell 中实现封装概念?
javaobject oriented programmingprogramming
Java Shell(简称 JShell)是一个 REPL 交互式工具，用于学习 Java 和原型化 Java 代码。它会评估输入的 声明、语句 和 表达式，并立即打印出结果并从命令行运行。
封装是 Java 中的一个重要概念，用于确保"敏感"数据已对用户隐藏。为了实现这一点，我们必须将类变量声明为私有变量，并提供对get 和set 方法 的公共访问权限，并更新私有变量的值。
在下面的代码片段中，我们为Employee类实现了封装概念。
jshell> class Employee {
...> private String firstName;
...> private String lastName;
...> private String designation;
...> private String location;
...> public Employee(String firstName, String lastName, String designation, String location) {
...> this.firstName = firstName;
...> this.lastName = lastName;
...> this.designation = designation;
...> this.location = location;
...> }
...> public String getFirstName() {
...> return firstName;
...> }
...> public String getLastName() {
...> return lastName;
...> }
...> public String getJobDesignation() {
...> return designation;
...> }
...> public String getLocation() {
...> return location;
...> }
...> public String toString() {
...> return "Name = " + firstName + ", " + lastName + " | " +
...> "Job designation = " + designation + " | " +
...> "location = " + location + ".";
...> }
...> }
| created class Employee
在下面的代码片段中，我们创建了一个 Employee 类的实例，并打印出 name、designation 和 location。
jshell> Employee emp = new Employee("Jai", "Adithya", "Content Developer", "Hyderabad");
emp ==> Name = Jai, Adithya | Job designation = Content Developer | location = Hyderabad.
