Class instances

Classes are of course used to instantiate new objects comprising fields and methods.

The well-known new operator is used in QED to instantiate objects. The equally popular . operator allows access to fields and methods.

Here the class declaration is the constructor, the a parameter and double local variable are fields and the nested function printDouble() is a method. Upon instantating the class, the obj instance contains both fields and the method, reachable by the . operator.

Classes are also first-class citizens.

A class interface can be created like a function interface. It can also be used with the * symbol to refer to a class pointer. The class can be instantiated and an instance object (without *) is returned.

All class members (fields and methods) are declared public. Private members can be embedded a wrapper plain builder function (which first letter is lowercase to not make it a class):

For pure class instantiation purposes, it is better to use the void return type when declaring its class, since the object will never return anything.

A word of caution here. QED classes, when compiled into JS code, generate Javascript classes as well. When using embedded JS code in a class and refer to one of its members, use <classname>$this (generated by the QED compiler) instead of the direct this pointer.

We only scratched the surface as to what QED classes can do. We’re just about to expand their functionality!