php - 删除php中字符串模式之后的所有内容

Question

我有一个模式列表:$allowedTLDS = array(".de", ".at", ".ch", ".org", ".com", ".eu");

现在我有像 <a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="093a393b383b3f3b3b646860654964706768646c276a6664" rel="noreferrer noopener nofollow">[email protected]</a> 这样的字符串我想剪掉 .com 之后的所有内容以获得普通邮件地址。 到目前为止我已经编写了这个函数:

function extract_correct_email_address($string){
    $allowedTLDS = array(".de", ".at", ".ch", ".org", ".com", ".eu");
    $foundMatch = false;
    $foundTLD = "";
    foreach ($allowedTLDS as $tld) {
        if (strpos($string, $tld) !== FALSE) {
            //found a match
            $foundMatch = true;
            $foundTLD = $tld;
            break 1;
        }
    }

    if($foundMatch){
        $str = strtok( $string, $foundTLD).$foundTLD;

        return $str;
    }


    return NULL;
}

现在我有例如这些地址，我可以在右侧获得输出:

input: [email protected] 
output: [email protected] 
expected: [email protected] (this one is correct)

input: [email protected] 
output: [email protected] 
expected: [email protected]

input: [email protected] 
expected: [email protected]

我希望人们可以理解我想要存档的内容。我在函数中做错了什么？

Answer 1

使用这个漂亮的正则表达式来实现 - 您只需添加 TLD:

function extract_correct_email_address($string){
    // pattern do match email addresses
    $pattern = '/[a-z0-9_\-\+]+@[a-z0-9\-]+\.(de|at|ch|org|com|eu)(?:\.[a-z]{2})?/i'; 
    preg_match($pattern, $string, $matches);

    if(count($matches[0])<1) {
        return null;
    }
    return $matches[0];
}


// example string         
$string = 'fdsaf das D <a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="2d454c435e446d59485e590349485a5a5a0341424103434859" rel="noreferrer noopener nofollow">[email protected]</a> <a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="680e1a090612280f010a1c1b46091c0c091b0e" rel="noreferrer noopener nofollow">[email protected]</a> dasf asd';
var_dump(extract_correct_email_address($string));

结果:

string(15) "[email protected]"

当然，您可以扩展它以用于提取多封电子邮件。而不是 matches[0] 检查所有匹配项。