Map and HashMap

33_maps_and_hashmap.dart

@@ -0,0 +1,46 @@
+
+// Objectives
+// 1. Maps
+// --> KEY has to be unique
+// --> VALUE can be duplicate
+
+void main() {
+
+	Map<String, int> countryDialingCode = {         // Method 1: Using Literal 
+		"USA": 1,
+		"INDIA": 91,
+		"PAKISTAN": 92
+	};
+
+
+	Map<String, String> fruits = Map();             // Method 2: Using Constructor
+	fruits["apple"] = "red";
+	fruits["banana"] = "yellow";
+	fruits["guava"]  = "green";
+
+	fruits.containsKey("apple");                        // returns true if the KEY is present in Map
+	fruits.update("apple", (value) => "green");         // Update the VALUE for the given KEY
+	fruits.remove("apple");                             // removes KEY and it's VALUE and returns the VALUE
+	fruits.isEmpty;                                     // returns true if the Map is empty
+	fruits.length;                                      // returns number of elements in Map
+//	fruits.clear();                                     // Deletes all elements
+
+	print(fruits["apple"]);
+
+	print("\n");
+
+	for (String key in fruits.keys) {           // Print all keys
+		print(key);
+	}
+
+	print("\n");
+
+	for (String value in fruits.values) {           // Print all values
+		print(value);
+	}
+
+	print("\n");
+
+	fruits.forEach((key, value) => print("key: $key and value: $value"));   // Using Lambda
+
+}