hash maps

CodeBase/Java_Intermediate/src/qa/com/hashMap/Country.java

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+package qa.com.hashMap;
+
+public class Country {
+
+	private String name;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public Country(String name) {
+		super();
+		this.name = name;
+	}
+
+	@Override
+	public String toString() {
+		return "Country [name=" + name + "]";
+	}
+
+
+
+
+}

CodeBase/Java_Intermediate/src/qa/com/hashMap/HashRunner.java

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+package qa.com.hashMap;
+
+import java.util.HashMap;
+import java.util.Map.Entry;
+
+// Hashmaps
+// Allow you to store information in a collection (Lists, ArrayLists, Maps) 
+// You store information with a index (Key) and data (Value) pair
+// A list of key value pairs (can be made up of any data types)
+public class HashRunner {
+
+	public static void main(String[] args) {
+
+		// We are creating a HashMap which takes in a String and a String
+		// Its called currencies
+		// Its created by returning HashMap<>()
+		HashMap<String, String> currencies = new HashMap<>();
+
+		// Add data to my HashMap by using put()
+		currencies.put("United Kingdom", "Pound Sterling");
+		currencies.put("France", "Euro");
+		currencies.put("Internet", "Dogecoin");
+
+		// Prints out the map with all the values
+		System.out.println(currencies);
+//		{United Kingdom = currency@com.qa.hash67272b29} 
+		// Happens if the object passing in doesnt have a toString
+
+		// Returns the length of the map
+		System.out.println(currencies.size());
+
+		// Get 
+		System.out.println(currencies.get("Internet"));
+
+		// Remove
+//		currencies.remove("France");
+		System.out.println(currencies);
+
+		// Looping
+		// keySet()   = The key (left of the map)
+		// values()   = The values (right of the map)
+		// entrySet() = The entire thing
+
+		for(String i : currencies.keySet()) {
+			System.out.println(i);
+//			currencies.remove(i);
+		}
+
+		for(String i : currencies.values()) {
+			System.out.println(i);
+		}
+
+		for(Entry<String, String> i : currencies.entrySet()) {
+			System.out.println(i);
+		}
+
+		// Hashmaps just like arraylists / lists can take in custom objects
+
+		HashMap<Country, String> currencies2 = new HashMap<>();
+		currencies2.put(new Country("USA"), "Dollars");
+		System.out.println(currencies2);
+
+	}
+
+}