Dart functions as first objects and using Alias

// we can define alias like so:

typedef Greet = String Function(String);

// Object of type Function, takes in param of type String,

// return type String

void welcome(Greet greet, String name) {

print(greet(name));

}

void main() {

final sayHi = (String name) => 'Hi, $name';

welcome(sayHi, 'Ricky');

}