flutter tutorial dart primer | https://www.youtube.com/watch?v=FLQ-Vhw1NYQ&list=PL4cUxeGkcC9jLYyp2Aoh6hcWuxFDX6PBJ&index=3

flutter-tutorial-part-00-dart-primer-basics.dart

//  Define main function
void main() {

//  00. HELLO WORLD  ============================
  
//   Hello World Program
  print('hello world');
  
//  01. DATA TYPES  ============================
  print('\n01. DATA TYPES: \n------------------------------');
  
//   Define int and check datatype
  int age = 31;
  print(age);
  print(age.runtimeType);
  
//   Define String and check datatype
  String name = 'numoonchld';
  print(name);
//   name = 30 // Throws "Error: A value of type 'int' can't be assigned to a variable of type 'String'."
  name = "Raghavendra"; // String overriding is allowed
  print(name);
  print(name.runtimeType);
  
//   Define boolean and check datatype
  bool isNight = true;
  print(isNight);
  print(isNight.runtimeType);
  
//   Dynamic datatype 
  dynamic word = "realize";
  print(word);
  print(word.runtimeType);
  
  word = 30; // No error thrown when overwriting with different data type
  print(word);
  print(word.runtimeType);

//  02. FUNCTIONS  ============================
  print('\n02. FUNCTIONS: \n------------------------------');
   
  String greeting() {
    return "Hello";
  }
  
  int getAge() => 31; // supports single-line arrow functions
    
//   Specifying ~void~ return type
  void voidFuncTest(){
//     return "hello"; // Not allowed to return anything - throws "Error: Can't return a value from a void function."
    print("Hello World");
    
    String greet = greeting();
    int age = getAge();
    print(age);
    print(greet);
  }
  
  voidFuncTest();
  
//  03. LISTS  ============================
  print('\n03. LISTS: \n------------------------------');
  
  // Dynamic Lists
  List fruit = ['apple', 'watermelon', 'plums'];
  print(fruit);
  print(fruit.runtimeType);
  
  fruit.add('banana');
  print(fruit);
  
  fruit.remove('apple');
  print(fruit);
  
  fruit.add(31);
  print(fruit);
  
  // Type-Defined Lists
  List<String> veggies = ['carrot','radish','turnip'];
  print(veggies);
  
//   veggies.add(31); // Throws Error: The argument type 'int' can't be assigned to the parameter type 'String'. 
  
  print(veggies.length);
  print(veggies[0]);
  
}