Return value of an assignment statement?

["Martin v. Löwis"]

> Hi all. In C, an assignment statement returns the value assigned.

No. C doesn't have an assignment statement. Instead, in C, assignment
is an expression (just like a binary operation or a function call);
that expression evaluates to the value assigned (i.e. the result is
the value, the assignment is just a side-effect).

What you consider the assignment statement is actually an expression
statement, of the syntax

   <expression> <semicolon>

So

   x = y;
   f();
   3+4;

are all the same kind of statement.

> In python, as far as I can tell, assignment statements don't return
> anything:

Right - that's because they are statements. No statement "returns"
a value - except for the return statement, of course, but it doesn't
return it in the sense that you could write

     foo = return 44

Because of the confusing meaning of "return", I find it better to
say that expressions evaluate to a value, not that they return
a value.

> The above example generates a SyntaxError.
> 
> Is this correct? I just want to make sure I've understood the
> semantics.

Please try to study more on the difference between expressions
and statements.

Regards,
Martin

P.S. Just to confuse matters: GNU C also has statement expressions,
of the form

   ({ int y = foo (); int z;
         if (y > 0) z = y;
         else z = - y;
         z; })

These are expressions, but allow the expressiveness of statements
(including variable declarations)