can we declare like this how many times the loop executes while(flag)

[thangam004]

flag=1;
while(flag)
{
}
if this is correct please explain me

[stdq]

Using the Open Watcom compiler, the above program worked fine, although it is necessary to declare (and initialize as done above) variable flag as being of a specific data type, for example as an integer:

int flag = 1;

When the program reaches the while loop, the condition is evaluated to 1, which is true, and it never changes, because there is no statement inside the while that performs such change. Hence, the program loops infinitely.

[Nepomuk]

In the C language there is no predefined primitives for the boolean values true and false. Instead, the integer 0 is interpreted as false and any other integer is interpreted as true. So, if you have the above code (with stdq's modification) it should work nicely in any C compiler. It wouldn't just work with that value though; here are a few that would also work:

int flag = 42;
while(flag) {}

or

int flag = 1337;
while(flag) {}

Or try this:

int flag = ++9000;
while(flag) {}

It should work too.
You can even go the other way around and actually calculate the result of an expression which you know will be true, such as

int flag = (7 == 7);
while(flag) {}

or

int flag = ! (1 > 2);
while(flag) {}

Here, true is always converted to 1 and false always to 0.

[donbock]

When you ask if this is correct, what are your concerns? Have they been addressed by the preceding responses?