Behavior of the for( ; ; ) statement

[packetgeek]

I'm wet behind the ears when it comes to PHP. In fact I'm reading through my how-to book and it tells me that if you write a for statement, leaving the second expression blank it becomes an infinite loop because the blank second expression evaluates to true and never fails out of the loop. Can someone help me to understand the logic behind that? It seems a little counter-intuitive because by convention "0", " " and any unmet condition will evaluate to false. As usual I'm trying to understand why things are the way they are instead of just saying ok. TIA.

[Anon]

the second part of "for" is the condition under which the loop stops. so if you leave it blank, it runs forever. because there is no condition to be met, see ?!

hmm.

[packetgeek]

Thank you. Thant does make sense. I guess what was confusing me is that a null will evaluate to a false in most/all cases, and the blank conditional in the for statement looks "null" due to it's empty state. But in reality it's more than null, it's completely undefined. Again, thank you it helps to see the logic process.