请问该如何使用java写一个类，如下：

Question

写一个类Student，包含两个属性String name和int age；要求覆盖toString()方法和equals()方法，使得直接输出Student对象时输出的是对象的name和age；并且当两个对象的name和age都相同时认为它们相等；然后写一个主方法测试以上定义。2,写一个程序，要求运行时从命令行输入不同的值打印不同的结果，若输入：male则输出“you are a boy!”；若输入：female，则输出“you are a girl!”；若输入其他值则输出“you are wrong!!”。

Answer 1

(1)
public class M
{
public static void main(String args[])
{
Students stu1=new Students("Ni",25);
Students stu2=new Students("Wo",30);
stu1.toString();
stu2.toString();
if(stu1.equals(stu2))
System.out.print("they are equal");
}
}
class Students
{
public String name;
public int age;
Students(String name,int age)
{
this.name=name;
this.age=age;
}
public String toString()
{
String str="name is :"+name+'\n'+"age is :"+age;
System.out.println(str);
return str;
}
public boolean equals(Students stu)
{
if((this.name==stu.name)&&(this.age==stu.age))
return true;
else
return false;
}

}
(2)
import java.util.*;
import java.io.*;
public class N
{
public static void main(String args[]) throws IOException
{
Scanner sc=new Scanner(System.in);
System.out.println("请输入一个字符串：");
String str=sc.next();
//String str1=new String()
if(str.equals("male"))
System.out.println("you are a boy!");
else if(str.equals("female"))
System.out.println("you are a girl!");
else
System.out.println("you are wrong!!");
}

}

Answer 2

1.
class Student{
String name;
int age;
public Student(String name,int age){
this.name=name;
this.age=age;
}
public String toString(){
return "你的姓名是："+name+"，你的年龄是："+age;
}
public boolean equals(Object another){
return name.equals(another.name)&&age==another.age;
}
}
//测试程序
public class TestStudent{
public static void main(String[] args){
Student student1,student2,student3;
student1=new Student("迈克尔·杰克逊",50);
student2=new Student("迈克尔·乔丹",50);
student3=new Student("迈克尔·乔丹",50);
System.out.println(student1+(student1.equals(student2)?"等于":"不等于")+student2);
System.out.println(student2+(student2.equals(student3)?"等于":"不等于")+student3);
}
}
2.
public class WhatIsYourSex{
public static void main(String[] args){
if(args.length==1){
if(args[0].equals("male")){
System.out.println("you are a boy!");
}
else if(args[0].equals("female")){
System.out.println("you are a girl!");
}
else{
System.out.println("you are wrong!!");
}
}
else{
System.out.println("you are wrong!!");
}
}
}

 

Answer 3

public class Student{
private String name;
private int age;
Student(String name,int age)
{
this.age = age;
this.name = name;
}
public String toString()
{
return this.name+this.age;
}
public Boolean equals(Object obj)
｛
Boolean isequals;
if(obj.name==this.name&&obj.age==this.age)
{
isequals = true;
}else isequals = false;
return isequals;
}
}

public class testStu{

public static void main(String[] args)
{
Student a1 = new Student("a1",18);
Student a2 = new Student("a1",18);
System.out.println("a1"+a1.toString());
System.out.println("a2"+a2.toString());
if(a1.equals(a2))
{
System.out.println("a1 equals a2");
} else System.out.println("a1 不等于 a2");

}
}

2：
public class test{

public static void main(String[] agcs)
{
try{
String flag = agcs[0];
switch(flag)
{
case "male":
System.out.println("you are a boy!");
break;
case "female":
System.out.println("you are a girl!");
break;
default:
System.out.println("you are wrong!!");
break;
}
}catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("没有输入参数");
}
}
}