CODEWITHSUNDEEP
phparrays
user3179854
user3179854

Reputation:

PHP check if first few characters of string are contained in an array

I am currently using this:

if(strtolower(substr($subject,0,3)) != 're:' and strtolower(substr($subject,0,3)) != 'fw:' and strtolower(substr($subject,0,1)) != '#' and strtolower(substr($subject,0,5)) != 'read:') {

to check if the first characters of the $subject variable are not equal to,

in uppercase or lowercase, how can i check exactly the same thing but by using items contained in an array instead?

like:

$array = array("re:", "fw:", "#", "read:");

Upvotes: 1

Views: 60

Answers (2)

deceze
deceze

Reputation: 522076

foreach (array('re:', 'fw:', '#', 'read:') as $keyword) {
    if (stripos($subject, $keyword) === 0) {
        echo 'found!';
        break;
    }
}

or

$found = array_reduce(array('re:', 'fw:', '#', 'read:'), function ($found, $keyword) use ($subject) {
    return $found || stripos($subject, $keyword) === 0;
});

or

if (preg_match('/^(re:|fw:|#|read:)/i', $subject)) {
    echo 'found!';
}

or

$keywords = array('re:', 'fw:', '#', 'read:');
$regex    = sprintf('/^(%s)/i', join('|', array_map('preg_quote', $keywords)));

if (preg_match($regex, $subject)) {
    echo 'found!';
}

Upvotes: 2

Ja͢ck
Ja͢ck

Reputation: 173562

You can wrap the functionality of matching a string against a set of prefixes in a function:

function matches_prefixes($string, $prefixes)
{
    foreach ($prefixes as $prefix) {
        if (strncasecmp($string, $prefix, strlen($prefix)) == 0) {
            return true;
        }
    }
    return false;
}

And use like this:

if (!matches_prefixes($subject, ['re:', 'fw:', '#', 'read:'])) {
    // do stuff
}

See also: strncasecmp

Upvotes: 0

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