Papillary thyroid cancer (also sometimes called papillary thyroid carcinoma) is the most common type of thyroid cancer. You may have even heard your doctor talk about metastatic papillary thyroid cancer (metastatic means that it has spread beyond your thyroid gland).
Classes can have special methods called constructors. A constructor is a method that is automatically called when an object is created. Constructors are used to perform operations at the time an object is created. Constructors typically initialize instance fields and perform other object initialization tasks.
In JavaScript, object creation is prototype-based instead: an object creating function can have a prototype property, and any object assigned to that property will be used as a prototype for the objects created with that function.