使用preg_grep查找匹配项

I need server to return complete IDs that contain an integer(single digit or more) sent in by a user to find a match. e.g I submit '5678', then server returns 12567891, 54356782, 90567811. Emphasis on '5678'. My code returns no results.

<?php
$per = array(456755643, 78567561, 443321, 33267554560, 44321122,   554367533, 3390);
$thr = 675;
if(isset($_POST['search'])){
    $jake = preg_grep(("/$thr+/", $per);
    foreach($jake as $value){
        print $value . br;
    }
}
?>

try this

$per = array(456755643, 78567561, 443321, 33267554560, 44321122,   554367533, 3390);
$thr = 675;
$jake = preg_grep("/$thr/", $per);
foreach($jake as $value){
    print $value . '<br>';
}

//result
456755643
78567561
33267554560
554367533