PHP或Regex：字符串与搜索模式中的所有字符匹配

Question

I need to build a regex that will look for the occurrence of all characters in an inputted string.

For example, if the user inputs "equ" as the search parameter, "queen" and "obsequious" would match, but "qadaffi" and "tour" and "quail" would not.

Obviously I'm trying the basic /[equ]/ pattern and it's looking for "at least one of".

If there's a basic PHP function that would do this without regex, then that would be acceptable. But sad.

Answer 1

/[equ]/ is a character class which means it matches just one character. Try /.*equ.*/ instead. I haven't used the php matching functions, so the .* 's might be unnecessary.

Edit: Apparently they're definitely unnecessary, so just use /equ/ .

Answer 2

yeah, agreed that simple for loop would be more efficient in your case.

assuming $query = "que"; and $input = "queen"; or anything else:

$matched = true;
$len = strlen($query); // or mb_strlen($query) if you have multibyte string in input
for ($i = 0; $i < $len; $i++){
    if (!strstr($input, $query[$i])){
        $matched = false;
        break;
    }
}

very primitive loop to begin with.

Answer 3

@sln @jancha

I've implemented a timer to measure the speeds. Oddly, I'm finding that the regex is faster than the loop in my code. Is this right?

$haystack = "Obsequious";
$needle = array('e','q','u');
$regex = "/^(?=.*e)(?=.*q)(?=.*u)/";

function trial(){
    GLOBAL $haystack;
    GLOBAL $needle;
    foreach ($needle as $n) {
        if (!strpos($haystack, $n)) return false;
    }
    return true;
}

function trial2(){
    GLOBAL $haystack;
    GLOBAL $regex;
    if (preg_match($regex, $haystack)) {
        return true;
    }
    return false;
}

print time_trial("trial");
print time_trial("trial2");

function time_trial($function, $iterations=100000){
    $before = microtime(true);
    for ($i=0 ; $i<$iterations ; $i++) { 
        call_user_func($function);
    }
    $after = microtime(true);
    $total = round($after-$before, 4);  
    return "Executed timed trial '$function' // $iterations iterations // $total seconds<br />\n";
}

Answer 4

Probably a regex is not the tool for this job. Not a php expert, but loop through each required character checking that it exists in the object string.

Otherwise, using a regex does about the same, but its slow and overkill:

/^(?=.*e)(?=.*q)(?=.*u)/