Menu
What does the extern keyword mean? I've seen that in front of an function declaration like
extern void DoFoo ... 
387
“extern” keyword is used to extend the visibility of function or variable. By default the functions are visible throughout the program, there is no need to declare or define extern functions. It just increase the redundancy. Variables with “extern” keyword are only declared not defined.
extern "C" specifies that the function is defined elsewhere and uses the C-language calling convention. The extern "C" modifier may also be applied to multiple function declarations in a block. In a template declaration, extern specifies that the template has already been instantiated elsewhere.
Extern is a short name for external. used when a particular files need to access a variable from another file.
extern gives a name external linkage. This means that the object or function is accessible through this name from other translation units in the program. For functions, this is the default linkage in any case so its usage (in this context) is usually redundant.
137
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
