PHP append a variable to the end of a string - php

Question

So here I want to append the id of the currently logged in user to the name of a table, like for example Rating_User_1, but the 1 here comes from the id of the logged in user. I assigned the id of the logged in user to $id, as shown below in the code, and append it to the table column name, but this doesn't work. I tried echoing the $id by itself and it works (i.e. it spits out the id of the logged in user but that's not what I want), but when I try to append it to the string in order to "emulate" the table name it doesn't work. Any tips on workarounds?
#foreach($data as $data)
<tr>
<td> {{$loop->iteration}} </td> <!-- add number to the row -->
<td>
<a href="{{ Url('reply_thread') }}/{{ $data->id }}" class="text" >{{ $data->Judul }}</a>
</td>
<td><?php $id = Auth::user()->id;
echo $data->Rating_user_[$id]; ?> </td>
</tr>
#endforeach
My controller:
function threads() {
$data=Thread::all();
return view('thread.thread', ['data'=>$data]);
}
and some of the tables in the table Thread has columns named Rating_user_1, Rating_user_2, etc.

Answer 1

Variable expansion sometimes needs curly braces to function properly. The following should work:
echo $data->{'Rating_user_' . $id}
See Variable Parsing - Complex Syntax for info on "curly brace" variable expansion.
While it doesn't look like you need it here, Variable Variables may also be useful to read up on. (aka, $a = 'b'; $b = 'hello'; echo $$a; // Same as "echo $b", outputs 'hello')

Answer 2

You could try:
#foreach($data as $data)
<tr>
<td> {{$loop->iteration}} </td> <!-- add number to the row -->
<td>
<a href="{{ Url('reply_thread') }}/{{ $data->id }}" class="text" >
{{ $data->Judul }}
</a>
</td>
<td>{{ $data->{'Rating_user_' . $id} }}</td>
</tr>
#endforeach

Answer 3

You have multiple options to achieve this, the first would be to call the property/method with the name stored in a variable:
$tableName = 'Rating_user_' . $id;
$tableName = "Rating_user_$id";
$data->$tableName;
You could also use curly braces to make a hot concat on the property/method call itself as #romellem suggested:
$data->{'Rating_user_' . $id}
$data->{"Rating_user_$id"}
If you are going to access the $data->Rating_user more than once I would recommend you the first approach, if not the second one is okey aswell.

Answer 4

I think that your code is almost correct, and I think it's better if you use double curly than use echo like:
#foreach($data as $data)
<tr>
<td> {{$loop->iteration}} </td> <!-- add number to the row -->
<td>
<a href="{{ Url('reply_thread') }}/{{ $data->id }}" class="text" >{{ $data->Judul }}</a>
</td>
<td>{{ $data->{'Rating_user_' . Auth::id()} }}</td>
</tr>
#endforeach