寻找更优雅的DO WHILE解决方案

Question

So I have some code centered around a do while loop.

string token;
var count = 0;      
var checkDataLength= data.Length == 16;

do
{              
    count = 0;
    token = GenerateToken(data, start, end);

    if (checkDataLength)
    {
        if (Mod120Check(token))
        {                      
            count += 1;
        }
    }

    if (IsCompliant(token))
    {
        count += 1;
    }
} 
while (count > 0);

return token;

Basically, I am generating a token and for this token to be valid, has to FAIL the Mod120Check and the IsCompliant check. I cannot change how those methods return the data.

While the above code works, I feel that its ugly and I was wondering if anyone had a better way of doing it?

Thanks

Answer 1

Try this:

do
{
    token = GenerateToken(data, start, end);
} 
while (checkDataLength && Mod120Check(token) || IsCompliant(token))

Just moving your conditions to the while .

(!) Notice that IsCompliant(token) will only be called if checkDataLength && Mod120Check(token) states false . It shouldn't cause any colateral effects, but it could, depending on what your IsCompliant method does.

Answer 2

You're right, it is ugly. You are using count in an unexpected way (it gets reset to zero at the top of every loop, and can go positive for two different reasons). When I see count , I expect something to start at zero and count up (or start high and count done). Try this instead:

• Change var count = 0; to var goodEnough = false; up at the top
• Remove the count = 0; statement
• Change the two count += 1; statements to goodEnough = true;
• Change the while (count > 0); to while (!goodEnough);

This emphasizes that you are starting in a "not good enough" state, and you will loop until some condition makes it good enough to continue past the loop.