function insert($table,$array){

    $array['password'] = md5($array['password'] );

    $keys = join(",",array_keys($array));

    $vals = "'".join("','",array_values($array))."'";

    $sql = "insert {$table}($keys) values({$vals})";

    mysqli_query(connect(),$sql);

    return mysqli_insert_id(connect());

}

该方法为何一直返回0？

在这调用

function addAdmin(){

    $arr = $_POST;

    if(insert("imooc_admin",$arr)){

        $mes = "添加成功！<br/><a href='addAdmin.php'>继续添加</a>|<a href ='listAdmin.php'>查看管理员</a>";

    }else{

        $mes = "添加失败！<br/><a href='addAdmin.php'>重新添加</a>";

    }

    return $mes;

}