What is wrong with these loops

[Mrankin]

I need to know what is wrong with each of the following loops, I am pretty sure they all have the same problem.

do
{
cout << "true" << endl;
}while(true);

while(true)
{
cout << "true" << endl;
}

for(;;;)
{
cout << "true" << endl;
}

[Moschops]

Work out when each loop stops looping.

[Mrankin]

???

[Moschops]

Okay, I'll go slower. When will the first loop stop?

[Ben Duncan]

I'll add to that.
What tells the first one that it must stop?

[Mrankin]

I don't know... endl?

[Moschops]

endl will cause the output to go onto a new line; nothing to do with the loop. Time to read up on how loops work:

http://www.cplusplus.com/doc/tutorial/control/

[zb0S216C]

A little confused are we, Mrankin?

std::endl is a stream manipulator. It has nothing to do with how the loop executes, only how the contents of the stream is printed.

A loop needs to stop sometime. In all three loops, you never actually specify when any of the loops should stop. There are two ways to stop a loop:

1) By using the break statement.
2) By testing against a condition.

This code segment demonstrates both:

while( true )
{
    if( /* Such and such is equal to false */ )
        break; // from the loop.
}

_Wazzak

[Mrankin]

Thank you very much for the help.
And yes much more than a little confused. I pretty much don't know what I am doing, I took this course online, the book has nothing to do with C++ just problem solving, so it is no help, and I am having trouble making myself think in a way that suits programming. Sorry if I annoyed anyone by not knowing what is going on.

[zb0S216C]

Why not have a browse through these books: http://www.freetechbooks.com/c-c-f3.html

If the book you're reading, as Americans like to say, sucks, obtain another book. And don't worry, nobody is annoyed, you're just confused as all; we've all been there.

_Wazzak