How can an array in php contain other arrays?

{Code...} is displayed normally, as shown in the preceding code. How do I implement the hobbyS1 array in $ fields? I am like $ fieldsarray ($ name1, $ sre1, $ hobbyS1); no, how should I put it? Thank you.

        $name1=$_POST['name'];        $hobbyS1=array();        $hobbyS1=$_POST['hobbyS'];        $sre1=$_POST['sre'];        $fields = array($name1,$sre1);        echo implode($fields);

As shown in the above code, it is displayed normally.
How do I implement the hobbyS1 array in $ fields?
Me like this
$ Fields = array ($ name1, $ sre1, $ hobbyS1 );
No,
How to put it? Thank you.

Reply content:

        $name1=$_POST['name'];        $hobbyS1=array();        $hobbyS1=$_POST['hobbyS'];        $sre1=$_POST['sre'];        $fields = array($name1,$sre1);        echo implode($fields);

As shown in the above code, it is displayed normally.
How do I implement the hobbyS1 array in $ fields?
Me like this
$ Fields = array ($ name1, $ sre1, $ hobbyS1 );
No,
How to put it? Thank you.

Var_dump ($ _ POST) to check whether there are any values. it is normal.

$ Fileds = array ($ name1, $ sre1); can be used later

array_push($fileds, $hobbyS1); OR$fields[] = $hobbyS1

After execution:

$fields = array($name,$sre1);

Usage:

$fields[] = $hobbyS1;

I tried it. yes.