Sample class and function in Dart

ClassTest.dart

class MyClass{
  String str = '';  
  MyClass(this.str);
}


void main() {
  MyClass obj1 = MyClass('obj1 initial');

  print(obj1.str);

  doSomething(obj1);  
  print(obj1.str);

  obj1 = doSomethingElse(obj1);
  print(obj1.str);
}



void doSomething(MyClass obj){
  obj.str = 'obj1 new string';
}

MyClass doSomethingElse(MyClass obj){
  return MyClass('obj1 new object');
  //OR => return obj..str = "obj1 new object";
}