Why is this loop not infinite?

delfarms

I've already queryed my data from the mysql databases and put it into $result
now i'm making it an array.
But when I started really looking at this code(I've used it before), I started thinking, why isn't this while loop infinite? I don't know if i just forgot to take my stupid pills for today, but i've been programming in php for a while now, and just want to know.... :o

while ( $row = mysql_fetch_array($result, MYSQL_ASSOC) ) {

foreach ($row as $col) {

  //do something

}

laserlight

Read the PHP Manual on [man]mysql_fetch_array/man

maxpup979

heh. I do that all the time myself....
but this one is easy. First, you have a finite result set. this is what is going to end the while loop. the conditional present in your while basically says that while there is a new row in the result set, move it into an array. So when you run out of result set rows, you exit the while loop.

laserlight

First, you have a finite result set. this is what is going to end the while loop.

Not quite. What ends the loop is the false value returned by mysql_fetch_array().

the conditional present in your while basically says that while there is a new row in the result set, move it into an array.

That's true, but it says nothing about why the loop should terminate. If there two rows in the result set, one could return the first row forever and still have a new row in the result set (which may be possible if the interface required some other function to be called to advance the row pointer). What makes the difference is that mysql_fetch_array() "moves the internal data pointer ahead", and returns "FALSE if there are no more rows".

maxpup979

A much better explanation LL....thanks for clarifying my poor attempt.