CODEWITHSUNDEEP
c++loopsconditional-statementsdo-while
Benjamin-Cox
Benjamin-Cox

Reputation: 129

How do I end this do while loop?

This is probably a very newbie question but I am just practising classes for C++ and cannot seem to get this do while loop to end under a boolean condition.

int main()
{
    bool endgame = false;
    string x;
    int choice;
    cout << "please choose the colour you want your bow to be:\n";
    cin >> x;
    Bow bow1(x);
    do
    {
        cout << "please choose what you would like to do\n";
        cout << "(1 draw bow\n(2 fire bow\n(3 end game";
        cin >> choice;

        if (choice == 1)
        {
            bow1.Draw();
        }
        else if (choice == 2)
        {
            bow1.Fire();
        }
        else
        {
            endgame = true;
        }
    }
    while (choice > 0 || choice < 3 || endgame == true);
    return 0;
}

Upvotes: 0

Views: 1936

Answers (4)

Bernhard Barker
Bernhard Barker

Reputation: 55649

Since you're using OR (||):

  • If 0 < choice < 3, the loop will obviously continue since both choice > 0 and choice < 3 are true, this is what we want.
  • However, if choice >= 3 (say 10), the loop will continue since choice > 0 is true
  • and if choice <= 0 (say -1), the loop will continue since choice < 3 is true.

Thus the loop will always continue for any value of choice (regardless of endgame's value).

Also, the loop will continue (instead of stopping) while endgame is true, which is set as soon as choice is given a value of not 1 or 2.

If you make it AND (&&) and reverse the endgame check, it should work:

while (choice > 0 && choice < 3 && endgame == false);

But really the choice > 0 && choice < 3 && is unnecessary since you're setting endgame once either of those conditions hold.

while (endgame == false);

This can be simplified to:

while (!endgame);

Upvotes: 4

Christopher Janzon
Christopher Janzon

Reputation: 1039

Here:

if(endgame) break;

Try putting that at the end of your loop.

Upvotes: 0

Mathieu Devost
Mathieu Devost

Reputation: 19

What you want is to stay in the loop as long as your endgame is false, so you only need to change your test in the while statement like this:

while (choice > 0 || choice < 3 || endgame == false)

Upvotes: 0

user529758
user529758

Reputation: 

do {
    if (exit_condition)
        endgame = true;
} while (endgame == true);

This will set endgame to true when the exit condition is met, then loop back, because you check for endgame being true and not false. You want

} while (!endgame);

instead.

Upvotes: 3

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