redefining variables without extern

This is a discussion on redefining variables without extern within the C Programming forums, part of the General Programming Boards category; Not to beat a dead horse, but to make sure: If the declaration of an identifier for a function has ...

  1. #16
    cas
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    Not to beat a dead horse, but to make sure:
    If the declaration of an identifier for a function has no storage-class specifier, its linkage is determined exactly as if it were declared with the storage-class specifier extern. If the declaration of an identifier for an object has file scope and no storage-class specifier, its linkage is external.
    extern is thus indeed redundant on function declarations, but not on object declarations. Object declarations, without storage-class specifiers, at file scope (that is, external declarations) have external linkage, but are not assumed to have the storage-class specifier extern.

    Because the first sentence of the quote isn't relevant to the previous discussion I assume you quoted it for completeness, but I wasn't certain; hence this post.

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    Quote Originally Posted by cas View Post
    Because the first sentence of the quote isn't relevant to the previous discussion I assume you quoted it for completeness
    Yes, that's right.

    Dave, thanks for the link.

    So if I have extern int i; at block scope, does that refer to a global variable unless there was a previous declaration of i at block scope? The extern int i; could be in an inner block and the previous declaration in an enclosing outer block, right?

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