Re: Infinite loop with for(), sizeof()

On 23 Jul, Steve Chadsey wrote: > Hello, > > I'm wondering what I'm doing wrong here, with the following code: > > ---[start]----- > <? > $names[0] = "Hello World "; > > for($i = 0;$i <= sizeof($names); $i++) { > print $i . "<br>\n"; > $names[$i] = trim($names[$i]); > } > ?> > ---[end]----- > > It runs until I stop it. > It does this with PHP/4.0.1pl2 on both a Solaris 2.6 box and a Linux > 2.2.14 box, both with apache 1.3.12. > > If no one else can reproduce this, then I'll feel really bad. > > -- > Steve Chadsey <schadsey@anathema.lightbridge.com> > Now playing: Time Is Coming > (Testament - "Practice What You Preach") > Don't feel bad - it can be reproduced. However it's no bug - you have forgotten that your array subscripts start at 0, but the sizeof gives you the number of elements in the array - always greater than zero if the arrray is not empty. Effectively, what you are doing here is adding an element to the array with each iteration after the first; thus sizeof($names) increases by one each iteration, as does $i where you increment it; thus $i will never be greater than sizeof($names). The solution is to modify the control structure as follows: for($i = 0;$i < sizeof($names); $i++) { Cheers -- David Robley | WEBMASTER & Mail List Admin RESEARCH CENTRE FOR INJURY STUDIES | http://www.nisu.flinders.edu.au/ AusEinet | http://auseinet.flinders.edu.au/ Flinders University, ADELAIDE, SOUTH AUSTRALIA