Lesson_05_Map_Simple_Values_Countries_Visited_Example.java

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// Hello World with Dr. Dan - A Complete Introduction to Programming from Java to C++ (Code and Course © Dan Grissom)
//
// Additional Lesson Resources from Dr. Dan:
//		High-Quality Video Tutorials: www.helloDrDan.com
//		Free Commented Code: https://github.com/DanGrissom/hello-world-dr-dan-java
//
// In this lesson you will learn:
//		1) Map Data structure
//			a) Declaring and initializing
//			b) Mapping a String to an integer (primitive)
//			c) Common methods: containsKey(), get(), put(), remove(), size(), keySet()
//			d) Normalizing String values for map keys
//			e) Iterating through map keys and getting associate values
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import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Lesson_05_Map_Simple_Values_Countries_Visited_Example {

	public static void main(String[] args) {
		
		// Simple welcome statements printed to screen
		System.out.println("Program Objective: Learn to use the Map data structure to map Strings to a primitive (integer).");
		System.out.println("===========================================================================");

		// Initialize Scanner to read in from user
		Scanner scan = new Scanner(System.in);

		// Initialize data structures and variables
		Map<String, Integer> mCountryToVisitorCount = new HashMap<String, Integer>();
		String country;

		// Add new countries to our set of visited countries until user says "Done"
		do {
			// Prompt user for country to visit
			System.out.print("Please enter a country you have visited (enter \"Done\" to stop): ");
			country = scan.nextLine().toUpperCase();
			
			// If the map already contains the country, increment the count (the value associated with the country/key)
			if (mCountryToVisitorCount.containsKey(country))
				mCountryToVisitorCount.put(country, mCountryToVisitorCount.get(country)+1);
			else // Otherwise, set the count to 1 for this country
				mCountryToVisitorCount.put(country, 1);
		} while (!country.equals("DONE"));
		mCountryToVisitorCount.remove("DONE");

		// Iterate through each unique value in the set (will print in no specific order)
		System.out.println("Your group has visited " + mCountryToVisitorCount.size() + " unique countries, listed below:");
		for (String c : mCountryToVisitorCount.keySet())
			System.out.printf("\t%s had %s unique visitor(s)\n", c, mCountryToVisitorCount.get(c));
	}

}