import java.util.Scanner;

public class PhoneBook {
    private String[][] phones;
    
    public PhoneBook(){
        phones = new String[100][5];
    }
    
    public void command(int cmd){
        switch(cmd){
            case 1 : addInfo(); break;
            case 2 : search(); break;
            case 3 : deleteInfo(); break;
            default : break;
        }
    }
    
    public void addInfo(){
        System.out.println("addInfo();");
        //添加通讯录
        //通讯录满的处理
    }
    
    public void search(){
        System.out.println("search();");
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入操作：\n 1 : byname\n 2 : byphonenum\n 3 : byphoneid");
        int cmd = sc.nextInt();
        switch(cmd){
            case 1 : searchByName(); break;
            case 2 : searchByPhoneNum(); break;
            case 3 : searchByPhoneId(); break;
            default : break;
        }
    }
    public void searchByName(){
        System.out.println("searchByName();");
        //通讯录搜索byName
    }
    public void searchByPhoneNum(){
        System.out.println("searchByPhoneNum();");
        //通讯录搜索byPhoneNum
    }
    public void searchByPhoneId(){
        System.out.println("searchByPhoneId();");
        //通讯录搜索byPhoneId
    }
    
    public void deleteInfo(){
        System.out.println("deleteInfo();");
        //通讯录删除
        //通讯录空的处理
    }
    
    public static void main(String[] args){
        PhoneBook pb = new PhoneBook();
        Scanner sc = new Scanner(System.in);
        while(true){
            System.out.println("请输入操作：\n 1 : addInfo\n 2 : search\n 3 : deleteInfo");
            int cmd = sc.nextInt();
            pb.command(cmd);
        }
    }
}

------解决方案--------------------
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//的地方自己填，架子打好了
Java code

import java.util.Scanner;

public class PhoneBook {
    private String[][] phones;
    
    public PhoneBook(){
        phones = new String[100][5];
    }
    
    public ……