<
programming> (Or case
statement, multi-way branch) A
construct found in most
high-level languages for selecting
one of several possible blocks of code or branch destinations
depending on the value of an expression. An example in
C is
switch (foo(x, y))
{
case 1: printf("Hello
"); /* fall through */
case 2: printf("Goodbye
"); break;
case 3: printf("Fish
"); break;
default: fprintf(stderr, "Odd foo value
"); exit(1);
}
The break statements cause execution to continue after the
whole
switch statemetnt. The lack of a break
statement after
the first case means that execution will
fall through into
the second case. Since this is a common programming error you
should add a comment if it is intentional.
If none of the explicit cases matches the expression value
then the (optional) default case is taken.
A similar construct in some
functional languages returns the
value of one of several expressions selected according to the
value of the first expression. A distant relation to the
modern
switch statement is
Fortran's
computed goto.
(1997-01-30)