Java-访问控制修饰符

访问控制修饰符可以修饰属性，方法，构造方法，类

private：私有访问权限控制，被private修饰属性，方法，构造方法只能在本类的内部调用，外界无法访问

public class Test1 {
    public static void main(String[] args) {
        Teacher teacher=new Teacher("刘英谦",18,100000);
        //因为在new调用Teacher类的构造方法，然后通过类内部构造方法来访问private修饰salary
        teacher.salary=200000;//报错，被private修饰的属性salary，不在Teacher外界访问
        teacher.age=25;
    }
}
class Teacher{
    String name;
    int age;
    private double salary;
    Teacher(String name,int age,double salary){
        this.name=name;
        this.age=age;
        this.salary=salary;
    }
}

public class Test1 {
    public static void main(String[] args) {
        Person person=new Person("乔峰",30,"123456");//通过调用Person构造方法，通过类内部构造方法来间接访问password属性
        System.out.print(person.password);//报错，main方法在Person这个类的外部，不能访问private修饰的任何方法或属性
    }
}
class Person{
    String name;
    int age;
    private String password;
    Person(String name,int age,String password){
        this.name=name;
        this.age=age;
        this.password=password;
    }
}

public：用public修饰属性或方法，可以被外界任意的访问
总结，一般企业开发中，属性一般用private修饰（为了提供其安全性），方法一般用public修饰，以方便外界调用

我们可以通过使用public修饰get/set方法来访问private修饰的属性

public class Test1 {
    public static void main(String[] args) {
        Student student=new Student();
        student.setName("小龙女");
        String name=student.getName();
        System.out.println(name);
    }
}
class Student{
    private String no;
    private String name;
    private int age;
    private int score;
    private String sex;
    private String classes;
//访问：设置值，获取值
    //获取值
    public String getNo() {
        return no;
    }
    //设置值
    public void setNo(String no) {
        this.no = no;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public int getScore() {
        return score;
    }
    public void setScore(int score) {
        this.score = score;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getClasses() {
        return classes;
    }
    public void setClasses(String classes) {
        this.classes = classes;
    }
}