Identifiers and Scope

Scope—the region of program code where it is legal to reference an identifier; also called scope of visibility or scope of access
Three categories: local scope, global scope, and class scope; at this point, we only have local and global scopes
Function names have global scope; once a function is declared (function declaration prototype), it can be used anywhere in the program
Variables and constants can have global scope if they are declared before main
Variables and constants declared within functions have local scopes; this is what we have been dealing with mostly
Local identifiers with the same name as a global identifier have precedence within the function
A block is defined as the region between a pair of curly braces
Functions also include their parameters in the same scope as the function body, which is between curly braces (a block)