double while, new feature in C++? [closed]

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I found that this compiles in Microsoft Visual C++ 20开发者_如何学Python10.

void main()
{
    int i=9;
    while (i>4)
    {
        i--; 
    }
    while (i>6);
}

Probably not.. the second while does not seems to have an effect

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Your

while (i>6);

does not have any effect. It's just a loop with an empty body:

while (i>6)
  ;

---

There is nothing unusual about it. It's two while statements, except the other one has an empty body. The bigger problem is void main.

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You have two separate while loops here. The second just has an empty body. Reformat to:

int i=9;
while (i>4)
{
    i--; 
}

while (i>6)
    ;

...and it might make more sense. In this case, i is 4 upon entry to the second loop, so the second loop never executes.

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while (i>6); is no new feature, it simply says that while i is greater than 6 it should execute an empty statement ;.