Re: Re: == and ===

On 4/19/05, Sara Golemon <pollita@php.net> wrote: > > <?php echo '0' == '0.0000e0' ?> > > 1 > > > > <?php echo '0' == 'asadoaskd' ?> > > (nothing, false) > > > > <?php echo '0' == (int)'adasd' ?> > > 1 > > > > That confuses me more (but understandable, and thank God PHP behave > > this way)... I thought 'asdasd' is 0 when [implicitly] converted to > > int [for comparison]? I guess I never knew PHP well :-( > > > That would be the 'Roughly Speaking' and 'not precisely how the engine > handles it internally' parts. > > In the case of string to string comparison there must be at least one digit > involved at the start of the string (or a plus/minus sign followed by > digits, etc...) in order to qualify as a numeric string. I don't see this is the case: <?php echo '0' == '0asodkaowueoq' ?> (false) <?php echo '0' == '0 asdkasod' ?> (false) Isn't '0asdkoasdk' a numeric string? However: <?php echo 0 == 'asodkasodk' ?> 1 (this is expected, although for the $password case, it can lead to security holes). More niceties: <?php echo null == 0 ?> 1 <?php echo null == '' ?> 1 <?php echo null == '0' ?> (false) Programming in PHP can be a lot of fun! ;-) -- Hendy Irawan http://www.gauldong.net http://dev.gauldong.net