Question

Creating a Perl Product Directory - A product "id" will be used to identify a product (the key) and the description will be stored as the value

• The program should print a menu asking you to "add" an entry, "remove" an entry, "lookup" an entry, "list" all entries, and "quit" to end
• The user will enter a number to select the menu item from above, 1, 2, 3, 4, or 5 respectively.

1. Asks the user to enter a product ID, then asks them to enter a description... the product ID is stored as the key of a hash and the description is the value
2. Asks the user to an ID, if that ID exists in the hash, that entry is deleted from the hash
3. Asks the user to an ID, if that ID exists in the hash, that entry's value is printed (the description)
4. Prints all the key/value pairs of the hash, each entry on a new line with with a colon or dash separating the ID from the description
5. Exits the program

• The program will continuously loop, that is, it will print the menu after each successful action... unless the user chooses 5 to quit, which will end the program. This can be achieved by either using a "while" loop or by using a subroutine that prints the menu after each successful action

Some code is provided to you as a template.

Answer 1

The following code is written in JAVA.

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import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class PerlDirectory {

  
public static void main(String[] args) {
/*
Create a hash map with an integer key and string description
*/
  
HashMap<Integer,String> map = new HashMap<Integer,String>();
boolean program = true;
while(program){
System.out.println("******************************");
System.out.println("---------MENU-----------");
System.out.println("1. ADD");
System.out.println("2. REMOVE");
System.out.println("3. LOOKUP");
System.out.println("4. LIST");
System.out.println("5. QUIT");
System.out.println("******************************");
  
Scanner sc = new Scanner(System.in);
System.out.print("Enter your choice : ");
int choice = sc.nextInt();
  
if(choice == 5){
//QUIT AND CLOSE THE MENU , END OF LOOP
program = false;
System.out.println("Menu closed");
}else if(choice == 4){
//LIST ALL ENTRIES
for (Map.Entry<Integer,String> entry : map.entrySet())
System.out.println(entry.getKey() + " - "+ entry.getValue());
  
}else if(choice == 3){
// LOOKUP FOR A PRODUCT IN HASH MAP
System.out.print("Enter product ID : ");
int product_id = sc.nextInt();
  
if(map.containsKey(product_id)){
System.out.println(map.get(product_id));
}else{
System.out.println("Key not found");
}
  
}else if(choice == 2){
// DELETE ITEM FROM HASH MAP
  
System.out.print("Enter product ID : ");
int product_id = sc.nextInt();
  
/*
Here containsKey() is a method which returns true or false depending on
whether the entered key is present in the map or not
*/
if(map.containsKey(product_id)){
map.remove(product_id);
System.out.println("Item successfully removed");
}else{
System.out.println("Key not found");
}
  
}else if(choice == 1){
System.out.print("Enter product ID : ");
int product_id = sc.nextInt();
sc.nextLine();
System.out.print("Enter description : ");
String description = sc.nextLine();
  
//ADD ITEM TO HASH MAP
map.put(product_id,description);
System.out.println("Item Added Successfully");
}else{
System.out.print("Incorrect Menu Item Selected");
  
}
  
}
}
  
}