const, final, var etc in Dart

main.dart

void main() {
  
  //Exercise 3
  
  //Question 1
  
  //Use the declared variables below to decide whether or not a person is eligible to rent movies
  //A person is eligible when the age is more than 20 and the person can show his/her ID 
  //An example printout: Eligible to rent movies? false
  
  int age = 15;
  bool id = true;
  
  print('Eligible to rent movies?  ${age > 20 && id}');
  
  //Question 2
  
  //Use the variable below and work out the price the customer will pay to enter the Wild Life Park
  //For a Bike, the driver will pay $10 entry
  //For a Car, the driver will pay $20 entry
  //For a Bus, the driver will pay $30 entry
  //Example printout: You will pay $10 to enter the Wild Life Park
  
  String type = 'Bike';
  print('You will pay ${type == 'Bike'? '\$10' :type =='Car'? '\$20' : '\$30' } to enter the Wild Life Park');
  
  //Question 3
  
  //Use the email declared below and test if it is a valid email address
  //For an email address to be valid, it must contain the @ symbol and a .
  //Example printout: Valid email address? true
  
  String email = '[email protected]';
  print('Valid email address? ${email.contains('@') && email.contains('.')} ');
  print('$email'.contains('@')? 'Valid email address': 'Not Valid');
  
  //Question 4
  //Look at the following declarations of variables. You need to change all the String declarations to
  //const, final or var
  //try this first on a piece of paper and then check it in coding
 
 const firstName = 'Peter';
  const lastName = 'Johnson';
  var fullName = '$firstName $lastName';
  final fullNameLength = fullName.length.toString();
  fullName = 'Peter Pollock';
  print(fullName);
 
}