constants and finals

Author: Aman Gupta

constants_and_finals.dart

@@ -0,0 +1,23 @@
+void main() {
+/*final: can only be set once and is initialized when accessed
+         - only consume memory if used
+  constant: implicitly final but it is compile-time constant
+            i.e. it is initialized during compilation - it will consume memory no matter
+                 if you're using it or not
+  NOTE: Instance var can be final but cannot be const.
+          - If you want a const at class level then make it static const
+            */
+
+  final cityName = "Delhi";
+  //String is optional
+
+  const double PI = 3.14;
+
+  Circle circle = new Circle();
+  print(circle.color);
+}
+
+class Circle {
+  final color = "Red";
+  static const PI = 3.14;
+}