Thread: What C++ loops can provide both zero and 1-trip behavior?

I think its a forever loop but can a for loop also do this?
Pls help.

Originally posted by correlcj
I think its a forever loop but can a for loop also do this?
Pls help.

What is it exactly that you are looking for. Do you mean a while loop?

do/while - posttest always one trip

while and for- pretest- 0 or more times

Those are the only three loops in C!

Originally posted by MrWizard
What is it exactly that you are looking for. Do you mean a while loop?

i would guess he's asking for one trip loops, but maybe thats just me

mister C has already outlined the answer tho

quick recap. The 3 types of conditional loop in c/c++ are :-
TOPTESTED LOOP
This is a while loop. The loop will continue while the condition is true.

Code:

while(1) // will loop forever. same as while(true)
{ // do something}

BOTTOMTESTED LOOP
This is a do/while loop. This type of loop always executes once and then the condition is tested and looping continues while condition is true.

Code:

do
{// do something}
while(condition);

COUNTED LOOP
This is a for loop. This type of loop occurs for a counted number of iterations. for instance this will loop 10 times.

Code:

for(int i=0;i<10;i++)
{// do something}

I think its a forever loop but can a for loop also do this?

A forever loop.

Maybe this?

Code:

#define EVER ( ;; )


 forEVER {


 }

/*edit*/...damn smilies...

COUNTED LOOP
This is a for loop. This type of loop occurs for a counted number of iterations. for instance this will loop 10 times.

Code:

for(int i=0;i<10;i++)
{// do something}

[/B]

that's a very poor and inaccurate way to describe a for loop.

Originally posted by Eibro
I don't see how for loops are counted and while/do..while loops are conditional. Most while/do..while loops are counted anyway (if not all)

int i = 0;
while (i < 10) { /* do something */ };
for (int i = 0; i < 10; i++) { /* do something */ };
int i = 0;
do { i++ /* do something else */ } while (i < 10);

All loops can be both counted and conditional, but for-loops are especially made to be counted and while-loops are made to be conditional.
Making for-loops conditional have no real purpose (it's way easier to use a while loop).

Examples of non-counted while loops:

Code:

bool Looping = true;
while(Looping)
{
   ...

   if(kbhit()) Looping = false;
}

Code:

while(GetMessage(...))
{
   TranslateMessage(...);
   DispatchMessage(...);
}

Edit:
If you want an easier counted loop function:

Code:

#define LOOP(n) for(int i=0; i<n; i++)

int main()
{
   LOOP(5) cout << i;
   LOOP(100) 
   {
      cout << "I'm the best!" << endl;
   }
   return 0;
}

What C++ loops can provide both zero and 1-trip behavior

That is the question posted to me in the book. Its asking for one or more than one loop(ie. while, do/while, forever or for) these can only be the answers. I can only assume that it must be them all and is a trick question. I am still

I understand that there are 3 types of loops really but c++ provides 4 different loops.
1. while
2. do
3. for
and forever which is a simpified for loop eg;

Code:

for ( ; ;)
{
    statement1;
        if (condition)    break;
            statement2;
}

but actually there are 3.
Thanks for the posts, i am going to say all of them and see how that flies. weird question?

The correct answer is the forever loop because it eliminates redundant coding and it can be used in both times where statements must be executed 0 or more times and other statements must be executed 1 or more.
THANKS! for everyones input!!