Express e stack - small items in array

Catalog

Function is introduced :

1. Role switching ( Couriers and ordinary users  

2. Deposit Express  

 3. Delete express

 4. Modify Express

5. Check out all the couriers  

6. Pick up express

Ideas ：

Reasons for stepping on the pit ： 

Code implementation

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Today's mission , Is to complete the express delivery E Stack ( Console easy version ) System . Variable passed , Process control , Learning of three parts of array , Let's work on a small project Consolidate these skills ！ Don't underestimate what we learned before , Now we can get through this Some knowledge points to complete a simple version , Express based on console version E Stack , In the process of completion , Big Home should master the application of knowledge , Also learn the business logic , For greater express delivery after us E Prepare for stack system implementation .

Function is introduced :

1. Role switching ( Couriers and ordinary users  

  Courier function : Deposit Express , Delete express , Modify Express , Check out all the couriers

  Ordinary user functions : Pick up express

2. Deposit Express  

 3. Delete express

 4. Modify Express

5. Check out all the couriers  

6. Pick up express

Ideas ：

1： The array can represent the express cabinet , Use traversal to find express , Create objects , It is equivalent to the access of an express cabinet .

2：switch The cycle is suitable for the project presented one by one , In this project for It is more suitable for the main loop

3： Properties of array subscripts , from 0 Subscript start , No matter how many subscripts there are =-1, utilize -1 To determine whether an object is created

Reasons for stepping on the pit ： 

I do not know! contentEquals() Methods and Math.random() Method

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Code implementation

package com.java.bean;
import java.util.Scanner;
public class ExpressArray {
    public static void main(String[] args) {// Main method 
        Scanner scan = new Scanner(System.in);// The console receives data 
        String[] OrderId = new String[10];// courier number 
        String[] comName = new String[10];// Express name 
        int[] codeGet = new int[10];// Pick up code 
        System.out.println(" Welcome to the express cabinet of new vocational course ======");
        System.out.println(" Please enter your identity information ： 1. Courier      2. user ");
        int num = scan.nextInt();// Receive integer type num1
        switch (num) {
            case 1:// Courier 
                System.out.println(" Please select ： 1. Deposit Express 		2. Delete express 	3. Modify the courier information 	4. View all express information ");
                int num2 = scan.nextInt();// Receive integer type num2
                switch (num2) {
                    case 1: // Deposit Express 
                        int index1 = -1;// Given index1 One -1 Value , Used to judge whether the express cabinet is full , Loop traversal 
                        for (int i = 0; i < OrderId.length; i++) {// Traversal array ,String The initial value of the type array is null
                            if (OrderId[i] == null) {// Check for null, If the object is saved, it is not null 了 
                                index1 = i;// If there is null, Just assign it to index
                                break;// The end of the statement 
                            }
                        }
                        if (index1 == -1) {// If index still -1 explain i Not given index assignment , Prove that all arrays are not null
                            System.out.println(" The express cabinet is full , Unable to continue depositing ");
                        } else {// Since you can walk to else, It indicates that the array is null, After a long time, the index of this array can be re assigned 
                            System.out.println(" Please input the express number ：");
                            String number1 = scan.next();// Input number1
                            OrderId[index1] = number1;// Will array OrderId[index1] Subscript assignment number1
                            System.out.println(" Please enter the courier company ：");
                            String company = scan.next();// Input company
                            comName[index1] = company;// take comName[index1] Subscript assignment company
                            int code = (int) (Math.random() * 100000) + 100000;//int Type of pick-up code code Assign one 1000 Number within 
                            codeGet[index1] = code;// above code It's a random six digit number , hold codeGet[index1] The subscript is assigned to him 
                            System.out.println(" The express has been deposited in , The pick-up code is " + code);// Output pick-up code 
                            break;// The end of the statement 
                        }
                        break;
                    case 2: {// Delete express 
                        System.out.println(" Please enter the courier number you want to delete ");
                        String number2 = scan.next();// Receive one string Data of type ,number2
                        int index2 = -1;// The same is given first index2 Subscript a -1 Value , Look for the heel number2 The same object 
                        for (int i = 0; i < OrderId.length; i++) {// After traversing the array , If there is any number The same object assigns it to index Subscript 
                            if ((number2).equals(OrderId[i])) {// If i The delivery order number of the subscript is followed by number2 same , Then find the target 
                                index2 = i;// Finding the target will i Assign a value to index
                                break;// end if sentence 
                            }
                        }
                        if (index2 == -1) {// If index still -1 explain i Not given index2 assignment , Prove that all subscript array data are not number2
                            System.out.println(" The express order No. does not exist ");
                        } else {// The program comes to this , explain index No -1,number2 Already found .
                            OrderId[index2] = null;// but index The three arrays under the subscript are all initial values , Express has been deleted 
                            comName[index2] = null;
                            codeGet[index2] = 0;
                            System.out.println(" The express delivery order number has been deleted ");
                        }
                        break;
                    }
                    case 3: {// Modify Express 
                        System.out.println(" Please enter the courier number you want to modify ");
                        String number3 = scan.next();// Receive one string Data of type ,number2
                        int index3 = -1;// The same is given first index3 Subscript a -1 Value , Look for the heel number3 The same object 
                        for (int i = 0; i < OrderId.length; i++) {
                            if ((number3).contentEquals(OrderId[i])) {
                                index3 = i;
                                break;
                            }
                            if (index3 == -1) {// If index3 still -1 explain i Not given index3 assignment , Prove that all subscript array data are not number3
                                System.out.println(" The express order No. does not exist ");
                            } else {// The program comes to this , explain index3 No -1,number3 Already found 
                                System.out.println(" Please enter a new courier number ");
                                String number4 = scan.next();// Receive one string Data of type ,number4
                                OrderId[index3] = number4;// Will array OrderId[index3] Subscript assignment number4
                                System.out.println(" Please enter a new express company ");
                                String newCompany = scan.next();// Receive one string Data of type ,newCompan
                                comName[index3] = scan.next();// take comName[index3] Subscript assignment company
                                int newCodeGet = (int) (Math.random() * 100000) + 100000;// Random number creation 
                                codeGet[index3] = newCodeGet;// Assign a six digit random number to the new pickup code newCodeGet
                            }
                            break;
                        }
                    }
                    case 4: {// Check out all the couriers 
                        int index4 = -1; // Judge whether the express cabinet is completely empty 
                        for (int i = 0; i < OrderId.length; i++) {// Traversal array 
                            if (OrderId[i] != null) {// As long as there is a subscript 
                                index4 = 0;// to index assignment 0
                                break;// The end of the statement 
                            }
                        }
                        if (index4 == -1) {// If index4 still -1 explain i Not given index4 assignment , Prove that all subscript array data are null
                            System.out.println(" The express cabinet is empty , No express delivery ");
                        } else {// The program comes to this , explain index4 No -1,index4 Assigned value 0
                            System.out.println(" All courier information is as follows ：");
                            System.out.println(" courier number \t Corporate name \t Pick up code ");
                            for (int i = 0; i < OrderId.length; i++) {// Traverse the array and output the new pickup code information 
                                System.out.println(OrderId[i] + "\t" + comName[i] + "\t" + codeGet[i]);
                            }
                        }
                    }
                    break;// End of cycle 

                }
            case 2:// user 
                System.out.println(" Please enter the pickup code ");
                int codeUser = scan.nextInt();// Receive one int Data of type ,codeUser
                int index = -1;// Match the pick-up code 
                for (int i = 0; i < OrderId.length; i++) {
                    if (codeGet[i] != 0 && codeGet[i] == codeUser) {
                        index = i;
                        break;
                    }
                }
                if (index == -1) {// If index still -1 explain i Not given index4 assignment , That is, there is no match to 
                    System.out.println(" The express was not found ");
                } else {// The program comes to this , Description has been matched 
                    OrderId[index] = null;// The pickup code is null, That was taken away 
                    System.out.println(" You have taken pieces successfully ");
                }
                break;
        }
    }
}