1

class Students{
    // define member variable
    private int age;
    private String name,gender,phone,address,email;
    // setter and getter methods.
    public void setAge(int age){
        if(age>120 || age<0){
            System.out.println("年紀不合法！");
            return;
        }else{
            this
 
.age = age;
        }
    }
    public int getAge(){
        return this.age;
    }

    public void setName(String name){
        if(name.length()>6 || name.length()<2){
            System.out.println("姓名不合法");
            return;
        }else{
            this.name = name;
        }   
    }
    public
 
 String getName(){
            return this.name;
        }

    public void setGender(String gender){
        this.gender = gender;
    }
    public String getGender(){
        return this.gender;
    }

    public void setPhone(String phone){
        if(phone.length()!=11){
            System.out.println("error phone number"
 
);
            return;
        }else{
            this.phone = phone;
        }
    }
    public String getPhone(){
        return this.phone;
    }

    public void setAddress(String address){
        this.address = address;
    }
    public String getAddress(){
        return this.address;
    }
    public void setEmail(String email){
        this.email = email;
    }
    public String getEmail(){
        return this.email;
    }
// 預設建構函式
    public Students(){
        this.name = "nobody";
        this.age = 0;
        this.gender = "男";
        this.phone = "10086";
        this.address = "address";
        this.email = "[email protected]";
    }
    // 帶成員變數的建構函式
    public Students(int age, String name, String gender, String phone, String address, String email){
        this.age = age;
        this.name = name;
        this.gender = gender;
        this.phone = phone;
        this.address = address;
        this.email = email;
    }
// 描述吃、喝、玩、睡的方法
    public void eat(){
        System.out.println("eat");      
    }
    public void drink(){
        System.out.println("drink");
    }
    public void play(){
        System.out.println("play");
    }
    public void sleep(){
        System.out.println("sleep");
    }
}
// main
public class t1{
    public static void main(String[] args){
        Students st = new Students();
        System.out.println(st.getAge());
    }

}

2.

//注意：同一級目錄下不用import Students類，本例所用的Students類在t1.java檔案中。
public class t2{
    public static void main(String[] args){
        // 定義一個數組，儲存多個student物件作為通訊錄資料
        Students[] st= new Students[3];
        st[0] = new Students(1,"name1","male","1233211","address1","email1");
        st[1] = new Students(2,"name2","male","1233212","address2","email2");
        st[2] = new Students(3,"name3","female","1233213","address3","email3");
        String str = args[0];
        // 是不否需要友好提示標誌位
        int flagFind = 0;
        for(int i=0;i<st.length;i++){
            // 可以通過name,email,address查詢
            if(str.equals(st[i].getName()) || str.equals(st[i].getEmail()) || str.equals(st[i].getAddress())){
                // 查詢到
                System.out.println("you find one student: "+st[i].getName());
                flagFind++;
            }
        }
        // 提示
        if(0==flagFind){
            System.out.println("the student didn't exist!");
        }
    }
}

3.github：原始碼下載地址