父类与子类继承关系Java

2、创建名为 Person 与 Student 的类，并让 Sudent 类继承 Person 类。
3、 Person 类包含姓名( name )、年龄（ age )、性别（ sex ）等属性
4、 Student 类包含学号（ number )、语文成绩（ chinese _ grade )、英语成绩( englishgrade )、数学成绩（ math grade ）等属性
5、 Student 类包含学生总成绩（ totalGrade )、平均 （ averageGrade ）等方法。

照这改改，顺便学习：

public class person {
String name; String sex; int age; public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getSex() {
return sex;
} public void setSex(String sex) {
this.sex = sex;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
}
public String toString(){
return null;
} public person(String name, String sex, int age) {
this.name = name;
this.sex = sex;
this.age = age;
} }

public class Student extends person {
long number;
int phi;
int eng;
int comp;
public long getNumber() {
return number;
}
public void setNumber(long number) {
this.number = number;
}
public int getPhi() {
return phi;
}
public void setPhi(int phi) {
this.phi = phi;
}
public int getEng() {
return eng;
}
public void setEng(int eng) {
this.eng = eng;
}
public int getComp() {
return comp;
}
public void setComp(int comp) {
this.comp = comp;
} public Student(String name, String sex, int age, long number, int phi,
int eng, int comp) {
super(name, sex, age);
this.number = number;
this.phi = phi;
this.eng = eng;
this.comp = comp;
}
public double aver(){
return (phi+eng+comp)/3;
}
public int max(){
return Math.max(Math.max(phi, eng), comp);
}
public int min(){
return Math.min(Math.min(phi, eng), comp);
}
public String toString(){
return null;
}
}

作业自己写哦