在PHP implode中将数组与字符串变量合并

Question

implode(',', $a);

I want to attach the $q variable in front of the $a so like this

implode(',', $q.$a); 

But that doesn`t work. How can i put 2 variables in a implode function?

$a is an array with domain names like "com, org" and $q is the text (string) you type in before the domain names will appear.

I get the following error:

invalid argument passed in line..

Whole code:

$a = ['nl','net','com','co'];
$q = $_REQUEST["q"];

$domain = explode(".", $q);
$ext = @$domain[1] ?: ' ';


if (empty($ext)) {
    echo implode(',',$a);
} else if (in_array($ext, $a)) {
    echo $q;
} else {
    $r = [];
    foreach ($a as $x) {
        if (strstr($x, $ext)) {
            $r[] = $x;
        }
    }
    echo (count($r)) ? implode(',',$r) : implode(',',$a);
}

Answer 1

If $a is an array and $q is the prefix string you can achieve that with 2 steps:

Add the prefix with:

$a = array("com", "co");
$q = "robot.";
foreach ($a as &$value)
    $value = $q.$value;

Second, use the implode:

echo implode(',',$a);

output is:

robot.com,robot.co

Edited

I think this will be more suitable for you:

$a = array("com", "co", "org");
$q = "robot.c";
$arr =  explode(".", $q);

$output = array();
foreach ($a as &$value) {
    if (substr($value, 0, strlen($arr[1])) === $arr[1])
        $output[]= $arr[0] . "." . $value;
}
echo implode(',',$output);

In this code you take the domain prefix and search for all domain name that may be fit for the prefix.

Notice that is this example we have domain org but he does not show up because your prefix is c