Rafael wrote:
(inline)
Adam Zey wrote:
Rafael wrote:
A single "=" it's an assignment, not a comparison; and though it
sometimes work, you shouldn't compare strings with "==", but using
string functions, such as strcmp()... or similar_text(), etc.
This is PHP, not C. Operators such as == support strings for a reason,
people should use them as such.
You shouldn't rely on what other languages do, but the one you're
working with; PHP has no explicit data-types and manages strings as PERL
does. Just as you say there's a reason why "==" supports strings,
there's also a reason (or more) for strcmp() to exists --it's just safer
to use strcmp() instead of "==", e.g: 24 == "24/7"
Safer, yes. And it'd be even better to do 24 === "24/7", in which case
you don't need a function call, it's probably faster (I'd imagine that
comparing equality is faster than finding out HOW close it is like
strcmp does), and as I mentioned, easier to read.
If you need to ensure type, (so that 0 == "foo" doesn't return true),
then you can use ===.
Using a function call that does more than you need when there is an
operator to achieve the same goal is bad advice.
I think you haven't encounter a "special case" to make you
understand "==" does NOT have the same behaviour as strcmp() It's just
like the (stranger) case of the loop
for ( $c = 'a'; $c <= 'z'; $c ++ )
echo $c;
I didn't say that it had the same behaviour, only the same goal; finding
out if two strings are equal. strcmp does MORE than that, it also finds
out how CLOSE they are. You almost never need that information, in which
case you're wasting processing time with a function call that does
something that you don't need. Come on, face it, how many times have
done anything with strcmp's return value OTHER than checking that it's
zero? I bet the cases are fairly rare.
Not to mention the fact that it leads to harder to read code. Which of
these has a more readily apparent meaning?
if ( strcmp($foo,$bar) == 0 )
if ( $foo === $bar )
That might be true, either way you need to know the language to
understand what the first line does and that the second isn't a typo.
=== is a basic operator. One has to assume that somebody writing code is
at least familiar with the basic operators. If not, well, asking them to
know what the function strcmp does and what it means when it returns
zero is just as onerous. If not more so. And again, strcmp wastes time
calculating information we don't NEED.
Regards, Adam.
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