Question

Write a program the declares and uses two parallel arrays. One array for storing the names of countries and a second array for storing the populations of those countries. As you can see per the following the Country name and it's corresponding Population are stored at the same element index in each array.

China	1367960000
India	1262670000
United States	319111000
Indonesia	252164800
Brazil	203462000
Pakistan	188172000
Nigeria	178517000
Bangladesh	157339000
Russia	146149200
Japan	127090000

In the main method write a loop which asks the user if they would like to look up a given country's population.  

• If No, then terminate the program
• If Yes,
  • Call a value returning method, no parameters required:
    • This method prompts the user: What country would you like to look up?
    • The value entered is returned from this method
  • Call a second value returning method, passing it the value returned from the previous method call (ie. The name of the Country being searched for)
    • This method searches the country names array to see if it's there.
    • If it is there (ie it's found), return the population corresponding to the country
    • If it is NOT there, return a -1 which indicates the country was not found in the Country array
  • Back in the main method output the Country name searched for and it's population if found or Not Found when Not Found

Answer 1

Implementation in JAVA:

code:

import java.util.Scanner;

public class Country_Population {

   public static void main(String[] args) {
      
//       create scanner class object
       Scanner s= new Scanner(System.in);
      
//       declare and initialize country and population array of type long and String
       String country[]= {"China","India","United_States","Indonesia","Brazil","Pakistan","Nigeria","Bangladesh","Russia","Japan"};
      
       long pop[]= {1367960000,1262670000,319111000,252164800,203462000,188172000,178517000,157339000,146149200,127090000};
      
       System.out.print("\nDo you want to search population for country : ");
      
//       user ask for continue
       String ans=s.next();
       s.nextLine();
      
//       if invalid inout
       if(!(ans.equals("Yes") || ans.equals("No"))){
          
           System.out.print("Invalid Input Re-enter Please - ");
           ans=s.next();
          
               }
      
//       loop untill user enter yes for continuition
       while(ans.equals("Yes")) {
          
          System.out.print("Enter country name : ");
         
//          ask user for country anme
          String con=s.next();
          s.nextLine();
         
//          get population
          long popu= getpop(country,pop,con);
         
//          print population
          if(popu!=-1) {
             
              System.out.println("Population in "+con+" is : "+popu);
             
          }
         
          else {
              System.out.println("Sorry! Country not found!!!");
          }
         
          System.out.print("\nDo you want to continue : ");
          
//          again ask for continuition
          ans=s.next();
          s.nextLine();
         
          if(ans.equals("No")) {
              System.out.println("Program Terminated \nThank you!!!");
              return;
          }
         
//          for invalid input
          if(!(ans.equals("Yes") || ans.equals("No"))){
              
               System.out.print("Invalid Input Re-enter Please - ");
               ans=s.next();
              
                   }
         
       }
      
   }
  
//   method will return population if found for cname'th index in pop array
//   else return -1 if not found
   public static long getpop(String[] country, long pop[],String cname ) {
      
       for(int i=0;i<country.length;i++) {
          
           if(cname.equals(country[i])) {
              
               return pop[i];
           }
          
       }
      
       return -1;
      
   }

}

SAMPLE OUTPUT:

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