java面试题三十 public,private,protected,default访问权限

1 考题描述：



 

2 答案

BD

 

3解析

B. no modifer既为default也就是friendly

 

3.1 public,private,protected,default访问权限图



3.2证明

 3.2.1 myeclipse类关系图如下



 

3.2.2 各个类的代码

Student.java

package com.inner;

public class Student {
public  String name = "zhangsan";
String email = "1254290201@qq.com";
protected int age = 13;
private String address = "广州";

public static void main(String[] args) {
Student student = new Student();
System.out.println("name = " + student.name);
System.out.println("email = " + student.email);
System.out.println("age = " + student.age);
System.out.println("address = " + student.address);
}

}

 

MyTest1.java

package com.inner;

public class MyTest1 {

public static void main(String[] args) {
Student student = new Student();
System.out.println("name = " + student.name);
System.out.println("email = " + student.email);
System.out.println("age = " + student.age);
System.out.println("address = " + student.address); //这行编译通不过

}

}

MyTest2MyTest2MyTest2MyTest2.java

package com;

import com.inner.Student;

public class MyTest2 {

public static void main(String[] args) {
Student student = new Student();
System.out.println("name = " + student.name);
System.out.println("email = " + student.email); //这行编译通不过
System.out.println("age = " + student.age); //这行编译通不过
System.out.println("address = " + student.address); //这行编译通不过

}

}