What kind of result is generated by variable comparison?

American_horizo

Hi, i need to keep trace of the value generated by this comparison

$a='lol'; $b='lol';
echo ('result:'.$a == $b);

I expect that it's showed "result:true" into the page, instead no string is pinted. Why ?

dalecosp

Because the boolean isn't returned in any printable form ... it's internal to the script.

Try this:

$a='lol'; $b='lol';
echo 'result:';
var_export($a == $b);

dalecosp

i need to keep trace of the value generated by this comparison

That would be done with a flag:

if ($a==$b) {
  $ab_equal = 1; //or "true", or some non-falsy value
}

...

if ($ab_equal) {
   do_something();
}

NogDog

Just a bit more info: when you do this...

echo ('result:'.$a == $b);

...the result of the comparison, which will be a Boolean true or false, will automatically be type-cast to a string as a result of the concatenation operator (and if that weren't involved, then by the echo itself). As described in the manual, "A boolean TRUE value is converted to the string "1". Boolean FALSE is converted to [FONT=Courier New]''[/FONT] (the empty string)."

American_horizo

@NoDog
So considering that $a==$b (true), it should print
result:1
Instead nothing is print

laserlight

Try:

echo 'result:' . ($a == $b);

. has a higher precedence than == so you were actually testing the equivalent of:

echo (('result:' . $a) == $b);

American_horizo

works thanks