I have a simple switch:
So if I pass number 3 to switch, will it preform actions on case 3, what about case 3, 4?Code:int sumnum = 3; switch(sumnum) { case 1: break; case 2: dosth(); break; case 3: //will it preform action here - yes case 3: case 4: //will it go here? break; }
I just figgured this wouldnt even allow me to compile..
Just out of curiosity, why do you have two of the same case at all?
My best code is written with the delete key.
Your case 1 is useless. the switch would work the same without. Having two case 3 probably won't compile. if it does, it will simply ignore the second. But there is no break after case 3, so it will continue doing the next case untill it encounters a break or exits the switch.
It is too clear and so it is hard to see.
A dunce once searched for fire with a lighted lantern.
Had he known what fire was,
He could have cooked his rice much sooner.
That's a prototype.Your case 1 is useless.
Duplicate cases are illegal. If you want case 4 to run too when case 3 activates, then it does what you want.
But it seems kind of strange way to me.
Last edited by maxorator; 11-08-2006 at 09:49 AM.
"The Internet treats censorship as damage and routes around it." - John Gilmore
I wanted to make less code and look better..
I needed two cases do the same thing, except one do something more..
>I needed two cases do the same thing, except one do something more..
Read that a few times, please. It's completely nonsensical.
My best code is written with the delete key.
Is that what you meant?Code:int sumnum = 3; switch(sumnum) { case 1: // Do something for case 1 only break; case 2: // Do something for case 2 only break; case 3: // Do something for case 3 only // drop through deliberately case 4: // Do something for case 3 and case 4 break; default: // Do something for default only break; };
The you do this:Originally Posted by l2u
Code:switch(sumnum) { case 1: //put code here break; case 2: dosth(); break; case 3: //do if sumnum=3 case 4: //do if sumnum=4, or after doing condition for sumnum=3. break; }
It is too clear and so it is hard to see.
A dunce once searched for fire with a lighted lantern.
Had he known what fire was,
He could have cooked his rice much sooner.
Forgetting to place a break after each case will only cause it to "fall through" to the next one anyway. I always make sure I end my cases with a break, it makes good sense, unless of course the idea of the program is to test the weakness in a switch statement that is
Double Helix STL
However, as King Mir shown, not always placing a break is what is intended.
Originally Posted by brewbuck:
Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.
EDIT:
> i wanted the same case to do the same thing
In that case, leave out the break in one of the cases, eg, case 3 and it will execute the second
after it has fallen through the first.
Does sound rather odd though...
Double Helix STL
Is that smart to do? Would you pros do that?
Of course they would. Why do you think the switch semantics include the ability to fall through different case statements?
EDIT: However, as a second thought, if your switch expression is built around the use of breaks and only one or another case statement doesn't have it, it doesn't hurt to place a comment reminding you and anyone else who reads your code, that is really intended.
Last edited by Mario F.; 11-08-2006 at 10:58 AM.
Originally Posted by brewbuck:
Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.
But if you are going to deliberately fall through different case statements, it's advisable to clearly comment it so that at a later date someone maintaining your code does "correct" your "mistake" inadvertently.
