Question about for and while loop

Question

Hello dear mates!

I am beginner at programming and have some doubts about loops. Okay, here goes little program:

private void button4_Click(object sender, EventArgs e)
{
int count = 0;

while (count < 10)
{
count = count + 1;
}

for (int i = 0; i < 5; i++)
{
count = count - 1;
}

MessageBox.Show("The answer is " + count);
}

Now here is the problem. I can not figure out why is the final result of this program 5? I have tested the while loop only to see what it will print out and it was only a number of 10. Why it did not print all numbers from 1 to 9 because count is 0 and there is condition that after every loop value increases by one until count is less than 10?

After that I have only tested for loop and its result was -5 and I really do not know why. Can someone enlighten me?

Final result of this program is 5 probably because the result of while loop which is 10 and the result of for loop which is -5 are subtracted. Why are they subtracted? Where is that part in the program?

Thank you mates in advanced!

Orlando Stevenson · Answer

Thank you Vulpes. I think I understand now.

Vulpes · Answer

Well the for loop on its own reduces the value of count by 5. So if you comment out the while loop count which starts off at 0 will end up as -5. My last sentence was only talking about the for loop which decrements (i.e. reduces by 1) the count variable on each of its five iterations.

Orlando Stevenson · Answer

Thanks mate for helping! Things are a bit brighter now. Can you tell me why would for loop only produce the result of -5? And the second question I will quote you:  Each time through the loop the count variable will be decremented by one. Do you speak about for loop?

Vulpes · Answer

The while loop continues to execute whilst the value of the variable count is less than 10. Initially count is 0 and is incremented by one each time through the loop. Consequently after 9 iterations its value will be 9 and the loop will then execute for the tenth and last time leaving count with a value of 10. The for loop will execute as long as the iteration variable i is less than 5. Initially i is 0 and so the loop will execute 5 times finishing when i equals 4. Each time through the loop the count variable will be decremented by one. So as it starts at 10 it will end up at 5 which is what the MessageBox shows.