Add additional informations about indirect field accessing of struct arrays

struct_arrays.m

@@ -10,6 +10,12 @@ patient(2).name = 'Ann Lane';
 patient(2).billing = 28.50;
 patient(2).test = [68, 70, 68; 118, 118, 119; 172, 170, 169];
 
+% if the index is not specified, patient.field returns
+% the fields of all its elements as multiple return values
+[name1, name2] = patient.name;
+assert(isequal(name1, 'John Doe'));
+assert(isequal(name2, 'Ann Lane'));
+
 % creates a new records 'age'; this will be created in all the other
 % entries; fields not specified here are set to []
 patient(3).name = 'New Name';
@@ -21,6 +27,10 @@ customer(1).billing = 30.0;
 customer(1).test = [];
 customer(1).age = 25;
 
+% acceess fields indirectly
+field = "name";
+assert(isequal(customer(1).(field), 'Enrico'));
+
 % concatenates patient and customer to create a new struct array
 v = [patient customer]; % or [patient, customer]