| Re: strpos() before str_replace()? Or, maybe strtr()? [message #184923 is a reply to message #184918] |
Sun, 16 February 2014 14:45   |
Christoph Michael Bec
Messages: 207
Registered: June 2013
Karma:
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Senior Member |
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Jason C wrote:
> I know that I'm talking about microseconds here, so this is really just for the sake of furthering my own education.
>
> I'm looping through roughly 100,000 values:
>
> $userArr = array(
> "something" => "anything",
> ...
> );
>
> foreach ($userArr as $key => $val) {
> $firstname = str_replace($key, "****", $firstname);
> $lastname = str_replace($key, "****", $lastname);
> }
>
> Both $firstname AND $lastname could contain any of the keys, but could only potentially contain one key each. It's likely, though, that neither will contain any of the keys.
>
> Would it be faster to use strpos() before each str_replace(), like so?:
>
> foreach ($userArr as $key => $val) {
> if (strpos($firstname, $key) !== false)
> $firstname = str_replace($key, "****", $firstname);
>
> if (strpos($lastname, $key) !== false)
> $lastname = str_replace($key, "****", $lastname);
> }
>
> My instinct is that it would be the same, if not marginally slower; allowing a potential computation time for 100,002 strpos() as opposed to 100,000 str_replace().
>
> Or, would strtr() be faster? I've never actually used this function in practice; I think it's a slow function, but have never tested it, and don't remember where I read that:
>
> $firstname = strtr($firstname, $userArr);
> $lastname = strtr($lastname, $userArr);
>
> Any other suggestions on what might be the fastest option?
Having the fastest option is surely less important than having a correct
solution, and there is an important semantic difference between
str_replace() and strtr(). Consider the following snippet:
$array = array('some' => 'any', 'anything' => 'nothing');
$name = 'something';
$keys = array_keys($array);
$values = array_values($array);
var_dump(str_replace($keys, $values, $name));
var_dump(strtr($name, $array));
This will output:
string(7) "nothing"
string(8) "anything"
--
Christoph M. Becker
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