What does extern mean in a function declaration?- An extern function or a member can be accessed outside the scope of the .cpp file in which it was defined.
- A variable, function or declaration that is defined with extern, allows to make the usage f variable, function by the remaining part of the current source file. The declaration does not replace the definition. The declaration of function or a variable is just to describe their use external to the current file.
- In case one identifier is declared with file scope, and an identifier that is declared external with the same name within a block refers the same object. In case no other identifier exists at file scope then the identifier will be linked to the external file.