Switch..Case Statement Question.

[Andy]

Can someone tell me if the following Switch...Case construct is valid?
I'm wanting to check for multiple values in the Case statement without
explicitly listing each values.
So for example, will case 1-35: work? If this would work, will it
consider all numbers between 1 and 35 inclusive of 1 and 35? Please let
me know if the following will work below:

switch(state){
case 1-35:
case 37:
do something_1;
break;
case 36:
do something_2;
break;
case 38-50:
do something_3;
break;
}
Thank you.
Andy.

[Evertjan.]

Andy wrote on 28 feb 2005 in comp.lang.javas cript:

Can someone tell me if the following Switch...Case construct is valid?
I'm wanting to check for multiple values in the Case statement without
explicitly listing each values.
So for example, will case 1-35: work? If this would work, will it
consider all numbers between 1 and 35 inclusive of 1 and 35? Please let
me know if the following will work below:
did you test it yourself? If not why not?
switch(state){
case 1-35:
case 37:
do something_1;
break;

this part will execute if "state" is -34 or 37,
because 1-35 is 34, I think.

But please test it yourself.
--
Evertjan.
The Netherlands.
(Replace all crosses with dots in my emailaddress)

[Lee]

Andy said:

Can someone tell me if the following Switch...Case construct is valid?
I'm wanting to check for multiple values in the Case statement without
explicitly listing each values.
So for example, will case 1-35: work? If this would work, will it
consider all numbers between 1 and 35 inclusive of 1 and 35? Please let
me know if the following will work below:

switch(state ){
case 1-35:
case 37:
do something_1;
break;
case 36:
do something_2;
break;
case 38-50:
do something_3;
break;
}

With less effort and much less wait time, you could have just tested
your sample code yourself. Your first case will match any state that
equals your index value of -34 (1-35).

[Andy]

I apologize for not having tested myself and wasted your time. Do you
or anyone else knows of a way to check for multiple values without
stating each one like if I'd like to check all values from 1 through 35
how would i do it?

Any help will be appreciated.

[Michael Winter]

Andy wrote:

Can someone tell me if the following Switch...Case construct is valid?
No.
I'm wanting to check for multiple values in the Case statement without
explicitly listing each values.

You cannot. The expression after the case keyword is compared for
strict equality (===) with the expression in the switch statement. In
other words,

switch(2) {
case '2': /* This statement list will not be evaluated. */
}

the statement list for case '2' will not be evaluated because the
expressions do not evaluate to the same type (one is a number, the
other is a string).

You have little choice but to use an if statement.

if(((1 <= state) && (35 >= state)) || (37 == state)) {
/* Between 1 and 35 (inclusive) or is 37 */
something_1();
} else if(36 == state) {
/* Is 36 */
something_2();
} else if((38 <= state) && (50 >= state)) {
/* Between 38 and 50 (inclusive) */
something_3();
}

[snip]

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

[Evertjan.]

Andy wrote on 28 feb 2005 in comp.lang.javas cript:

I apologize for not having tested myself and wasted your time. Do you
or anyone else knows of a way to check for multiple values without
stating each one like if I'd like to check all values from 1 through 35
how would i do it?

Please do not use usenet as a form of email. you are replying to many
here, so quote relevant part of the mail you answer on. Remember
netiquette.

Now "I" have to quote from your old posting:switch(state ){
case 1-35:
case 37:
do something_1;
break;
case 36:
do something_2;
break;
case 38-50:
do something_3;
break;

You could do:

state = 20;
switch(true){
case state>=1&&state <=35:
case state==37:
do something_1;
break;
case state==36:
do something_2;
break;
case state>=38&&stat e<=50:
do something_3;
break;
case default:
alert('default' )
}

This however in my view defies usefulness of switch().
anyway if-else is much more robust:

state = 20;
if ((state>=1&&sta te<=35)||state= =37){
do something_1
else if (state==36)
do something_2
else if (state>=38&&sta te<=50)
do something_3
else
alert('default' );

[not tested]

--
Evertjan.
The Netherlands.
(Replace all crosses with dots in my emailaddress)

[Mark Preston]

Andy wrote:

I apologize for not having tested myself and wasted your time. Do you
or anyone else knows of a way to check for multiple values without
stating each one like if I'd like to check all values from 1 through 35
how would i do it?

Any help will be appreciated.

This is where the "greater than or equal to" and "less than or equal to"
operators come in handy. For instance, ">=1 && <=35" is between one and
thirty-five.

[bumbleguppy]

You can also try

switch(true){

case(val>1 && val<35): do something;break ;
case(val>=35 && val <53):do something;break ;

[Evertjan.]

bumbleguppy wrote on 05 mrt 2005 in comp.lang.javas cript:

You can also try

switch(true){

case(val>1 && val<35): do something;break ;
case(val>=35 && val <53):do something;break ;

[please quote, usenet is not email]

is the above really more useful than:

if (val>1 && val<35) do_something;
if (val>=35 && val<53) do_something;

?

--
Evertjan.
The Netherlands.
(Replace all crosses with dots in my emailaddress)

[rh]

Evertjan. wrote:

bumbleguppy wrote on 05 mrt 2005 in comp.lang.javas cript:

You can also try

switch(true){

case(val>1 && val<35): do something;break ;
case(val>=35 && val <53):do something;break ;

[please quote, usenet is not email]

is the above really more useful than:

if (val>1 && val<35) do_something;
if (val>=35 && val<53) do_something;

?

I'd have to say "No", because the former is syntactically (block)
deficient. ;-)

However, the "switch/case" idiom can be more useful, or at least more
appropriate to use, in some circumstances because of the nature of the
structural encapsulation it provides for a specific filtering task.

The choice shouldn't have any effect on the result of the execution,
but it can have a marked effect on the readability and maintainability
of the code.

../rh