Const and Final, Dartpad, samples of what can and cannot be edited, for a String and a Map

final_const_dartpad_Nov2021.dart

// Note: Although a final object cannot be modified, its fields can be changed. In comparison, a const object and its fields cannot be changed: they’re immutable.

void main() {
  const String name='Howard';
  final stats= {'age': 42, 'income': 0};
  const unchangeableStats={'hair': "black", "race": "chinese"};
  var normalMap= {};
  
  print("My age is ${stats['age']}");
  stats['age']=stats['age']!.toInt()+1;
  print("My age is ${stats['age']}");  
  stats['age']=stats['age']!+1;
  print("My age is ${stats['age']}");  
  
  stats['wisdom']=7; // adding fields to a "final" Map variable is not allowed except for ints. This is okay
  print("${stats['wisdom']} wisdom");
//  stats['strength']="not much"; // this is not okay. At compile time.
  print("${stats['strength']} strength");  
  
  print("My race is ${unchangeableStats['race']}");  
//   unchangeableStats["race"]="global"; // run time error, because i'm trying to change a value pair
//   print("My race is ${unchangeableStats['race']}");  
  
  print("My name is ${name}");
  
  normalMap["a"]=1;
  normalMap["b"]="textGoesHere";
  // putting strings or ints into a normal map is fine.
  
  print(normalMap);
  
//   name="SecretAgent";  // compile time error
//   print("My new name is ${name}");  

}