I guess that a declaration can be a definition,
since it is one in the same, true
int x; //declaration
int x = 5; //declaration and definition
Brett McCoy <[EMAIL PROTECTED]> wrote: On Feb 17,
2008 8:36 PM, Robert Ryan <[EMAIL PROTECTED]> wrote:
> what is the difference between a declaration and a definition in C++.
> can a declaration be a definition........ does a declaration just give a
> type, but a definition gives a type and reserves memory location int a; -
> a declaration
> int a =2; a definition
A declaration is a statement that show you intend to use a variable,
although it may be *defined* somewhere else.
Defining a variable means you have assigned an initial value to it.
For most types of variables, even if you have declared them, you can't
use them until you give them an initial value.
A declaration and a definition can be done at the same time for some
variables. In C, you can only declare a variable at the beginning of
scope. In C++, you can declare a variable anywhere inside a scope;
although I tend to still declare all of my variables at the beginning
of a scope just because it's all done in one place and it's neat and
tidy. Loop variables are the exception.
Sometimes the definition of a variable is done outside the current
scope (even file scope), but you still need to declare the variable
before you use it (like for extern variables defined in another
module). Many times the declaration of global variables like this are
done in a header file.
-- Brett
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