Polymorphism:
C++ - Must turn on with keyword virtual; activated when a base class pointer is pointed at an object of a type in the class' heirarchy. 
- If a base class pointer is pointed at a subclass where there is an overwritten function F that is not declared virtual, polymorphism does not occur, and a call of F will call the same version as the one declared in the type the pointer is declared in.

Ada, Java, - Occurs automatically; can't be 'shut off'

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Scope rules:

- Upward and outward from inside a block
- The interior of a block is invisible externally
	- Name and parameters (types only) are only things visible