Laine at 19:10, 11 June 2007

Laine — Mon, 11 Jun 2007 19:10:23 GMT

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==Description==

A block is a special statment, that begins with '{', contains
a list of statements, and ends with '}'.

The block may define local variables. If for a variable no
initialisation is given, the variable is initialised to 0 every
time the block is entered. Otherwise, the initialisation
expression is evaluated and its result assigned to the variable
everytime the block is entered.

Example definitions are:

int i;
int j = 3;
int k = 3 * j, l;

Here, i and l are both initialised to 0; j is initialised
to 3, and k is initialised to 9 (3 * j).

Local variables defined in a block are visible only until the
end of the block. Definitions in an inner block hide definitions in
outer blocks.

==History==

Up to 3.2.7, local variables were visible (from their point of
definition) in the whole function. That is, code like

do {
int res;

res = ...
} while (res == 5);
write(res);

was perfectly legal. It is no longer, as 'res' ceases to exist
with the closing '}' of the while().

You can get this old behaviour back with the #pragma no_local_scopes.
To turn it off again, use #pragma local_scopes.

Up to 3.2.8, local variables could not be initialised in their
definition.

Man block - Revision history

Laine at 19:10, 11 June 2007