There is no "continue" for switch?

[xz]

What if I want the following:

vector<intv;

// v is loaded by push_back()

switch( v.size() ) {
case 2:
//do something

case 4:
//somehow delete two element
//and then do the same thing as in case 2

case 6:
//somehow delete two element
//and then do the same thing as in case 4

default:
//...
}
I thought using "continue" to implement this but got this:

continue statement not within a loop

[Jerry Coffin]

In article <01db3ce8-2e5e-470d-a892-
0e**********@b1 g2000hsg.google groups.com>, zh*********@gma il.com says...

[ ... ]

well, I gave a case not so tough, what if a case a little tougher?

vector<intv;

// v is loaded by push_back()

switch( v.size() ) {
case 2:
//do something

case 4:
//somehow delete two element
//and then do the same thing as in case 2

case 6:
//somehow delete *four* element
//and then do the same thing as in case 2

default:
//...

}

i.e. I want to go to case 2 both after I treat the case 4 and case 6.

Truth to tell, I doubt I'd use switch at all for this. Rather, I'd do
something like this:

if (x == 2 || x == 4 || x == 6) {
v.erase(v.begin ()+2, v.begin()+x-2);
// do something
}
else
// whatever was in your default.

Of course, you'll probably need to make minor changes to account for the
position in the vector where you want to do the deletion.

--
Later,
Jerry.

The universe is a figment of its own imagination.

[Alexander Dong Back Kim]

On Mar 19, 2:46 am, xz <zhang.xi...@gm ail.comwrote:

What if I want the following:

vector<intv;

// v is loaded by push_back()

switch( v.size() ) {
case 2:
//do something

case 4:
//somehow delete two element
//and then do the same thing as in case 2

case 6:
//somehow delete two element
//and then do the same thing as in case 4

default:
//...

}

I thought using "continue" to implement this but got this:

continue statement not within a loop

Hi Zhang,

It seems you wanna to something like spaghetti code can do. Are you
originally from Basic language? =) I think Junchen's approach is a
right way to do it.

Cheers,
Alex

[Alexander Dong Back Kim]

On Mar 19, 9:32 am, Paul Brettschneider <paul.brettschn [e-mail]>
wrote:

xz wrote:

What if I want the following:

vector<intv;

// v is loaded by push_back()

switch( v.size() ) {
case 2:
//do something

case 4:
//somehow delete two element
//and then do the same thing as in case 2

case 6:
//somehow delete two element
//and then do the same thing as in case 4

default:
//...
}

I thought using "continue" to implement this but got this:

continue statement not within a loop

Of course there is a continue for switch (for your example else-thread):

#include <iostream>

void f(uint8_t n)
{
std::cout << n << '\n';
switch(n) {
for(;;) {
case 2:
std::cout << "do_something\n ";
break;
case 4:
std::cout << "somehow delete 2 elements\n";
continue;
case 6:
std::cout << "somehow delete 4 elements\n";
continue;
default:
std::cout << "default\n" ;
break;
}
}

}

int main()
{
f(2);
f(4);
f(6);
f(1);

}

HTH,
Paul

I didn't know that ;)

Cheers,

[jason.cipriani]

On Mar 18, 6:42 pm, Paul Brettschneider <paul.brettschn [e-mail]>
wrote:

Paul Brettschneider wrote:
Here is the correct solution (I think):

Yes; it works. Although I think using "goto" would have actually been
clearer here... at least with goto you know that it's going to jump
somewhere and you have to look for a label; whereas with your solution
I found that I first consulted the standard to verify that "continue"
was not for "switch" before looking very closely to see the "for (;;)"
hidden in there.
Jason

>
#include <iostream>

void f(int n)
{
std::cout << n << '\n';
for(;;) {
switch(n) {
case 2:
std::cout << "do_something\n ";
break;
case 4:
std::cout << "somehow delete 2 elements\n";
n -= 2;
continue;
case 6:
std::cout << "somehow delete 4 elements\n";
n -= 4;
continue;
default:
std::cout << "default\n" ;
break;
}
break;
}

}

int main()
{
f(2);
f(4);
f(6);
f(1);

}