variable variables session and array

leonoble

Hi all,

Couple of problems, one can anyone tell me how to register a session variable variable, is this possible?

Second I have an array variable variable setup like thus

${$array_name}['array_key'] = "array value";

but when I try to display the value.

echo "${$array_name}['array_key']"

I get Array['array_key']

can anyone help on either or both problems

thanks

Leon.

noiseusse

What's with the curly brackets? Something I don't know?

When you echo() a variable you don't need "quotation" marks just use echo($variable);

to register a session variable:

$my_var = 'stuff';
session_register('my_var');
echo($_SESSION['my_var']); // output: 'stuff'

suntra

Noiseusse's code is bad because we must not mix session_register() and $_SESSION... Here are two ways to register a session variable and display it.

<?
 // First way (not recommended)
 $my_var = "stuff"; 
 session_register("my_var"); 
 echo $my_var;
?>

<?
 // Second way (recommended)
 $_SESSION["my_var"] = "stuff";
 echo $_SESSION["my_var"];
?>

By the way, PLEASE do not post a message in different forums. One is enough...

=> http://www.phpbuilder.com/board/showthread.php?s=&threadid=10240199

kevinsequeira

$array_variable = "some_value";
$array_name = ${$array_variable};
$array_name = array();
echo $array_name['key value'];

maybe this will work ..

suntra

kevinsequeira's code would not work because...

<?
$array_variable = "some_value"; // Ok, the variable is defined.
$array_name = ${$array_variable}; // Ok, we get the array corresponding to $array_variable;
$array_name = array();  // Oops, we reset the array... all datas of $array_variable array is lost...
?>

Just remove that line and it will work. (I wrote the same thing in another forum...)

kevinsequeira

$array_name = array(); // Oops, we reset the array... all datas of $array_variable array is lost...

that was the code only to generate a variable array name, the array is populated later . it cant be reset if it hasnt been populated right and it couldnt have been populated cause the name was just created.

reg
kevin

suntra

I tried something :

<?
 $coco = array(1, 2, 3);
 $array_variable = "coco"; 
 $array_name = ${$array_variable}; 
 $array_name = array(); 
 echo $array_name[0]; 
?>

I got : Notice: Undefined offset: 0 in [...] on line 6

But with :

<?
 $coco = array(1, 2, 3);
 $array_variable = "coco"; 
 $array_name = ${$array_variable}; 
// $array_name = array(); 
 echo $array_name[0]; 
?>

I got : 1

That's what I wanted to get...

So when you write array() after the variable has been defined with the contents of ${$array_variable} it resets the contents.

kevinsequeira

what you say is true, but the point being here that only a variable array name has been defined, it has not been defined with any contents !!!

$array_variable = "some_value";
$array_name = ${$array_variable};
$array_name = array();

some_value is just a variable its not been defined as an array as in your example.

reg
kevin

leonoble

Thanks

I know how to register a session variable, it is a session variable variable that I can't seem to get the hang of.

I tried

session_register('{$array_name}')

and

session_register('$array_name'}

with regard to the second problem. I am going through an mysql_fetch_array, one of the values of which I would like to use for the array_name. This is a unique value which I can then assign various properties and their values that are related to the unique array name.

This means I will have several unique arrays with related properties.

I don't think

$array_variable = "some_value";
$array_name = ${$array_variable};

will work, because you are only assigning "some_value" to $array_name, once you start assigning values

$array_name['property'] = "value"

then it will just create this variable as an array. Also $array_name would not be unique.

I need to be creating an array

${$unique_value}['property'] = "value"

but I get the problem I detailed in my first post.

kevinsequeira

$array_variable = "some_value";

is a generic example, you replace "some_value" with whatever name you need to, in this case $unique_name from your table ..

and you're right you dont need to $array_name = array(); once you start assigning $array_name['property'] = "value" it will take it as an array

have u tried
session_register('array_name') instead of
session_register('$array_name')
reg
kevin

leonoble

Yes I realise what you are saying,

but by putting $array_variable = "whatever_value";

and then you say

$array_name = ${$array_variable}

is the same as saying

$array_name = "whatever_value";

then by assigning

$array_name['key'] = value

$array_name now becomes an array, im not sure if it places "whatever_value" at the start of the array, slightly off topic.

I want to call my array "whatever_value" which I should be able to do by

$array_variable = "whatever_value";
${$array_variable}['property'] = "value";

but when trying to display the value

echo "${$array_variable}['property']";

I get the error in my first post.

suntra

A little error...

When using session_register(), you must not put the $ sign...

<?php
$barney = "Un gros dinosaure violet.";
session_register("barney");
?>

I never use it, so excuse me of my error... !

Also, for the second problem...

Create a temporary array that will always have the same name, and at the end, put this array in ${$array_variable}...

<?
 $tempArray = array();
 $tempArray[0] = 1;
 $tempArray[1] = 2;
 $tempArray[2] = 3;
 $array_variable = "anything";
 ${$array_variable} = $tempArray;
?>

leonoble

I stuck my dynamically created arrays through a foreach and the keys and values are certainly stored.

It is when I try to access them individually, which I need to do, that I get errors.

currently I access them

echo "${$unique_value}['property']";

['property']

is then displayed.

suntra

Maybe if you try...

<?
echo ${$unique_value}['property'];
?>

leonoble

Solved it, you need to assign the value to another variable

$value = ${$unique_value}['property'];

echo $value

For some reason it does not display

${$unique_value}['property']

properly with an echo statement.

Just the session variable variables to sort out now although I may use a two dim array.

thanks for all your help, if anybody does know how to use session variable variables please post.

thanks

suntra

Do you mean how to store an array in a session ?

leonoble

well the array we are just talking about yes.

${$unique_value}

I am trying to store this as a session variable

thanks

suntra

It doesn't work if you try to register the array ?

<?
session_register(${$unique_value});
?>

You could also try with serialize()
http://www.php.net/manual/fr/function.serialize.php

You register the variable after you have serialized it...

minorgod

First of all, the curly bracket notation is just used to separate the variable you want substituted, from it's actual declaration. It's only necessarry when using dynamically named arrays so php doesn't get confused. There's good documentation on this at www.php.net.

$variablename="name";
$$variablename="kenny";

echo $$variablename."<br>"; //should output "kenny"
echo $name; //this should also output "kenny"

Also, don't use session_register at all if you've got access to $_SESSION superglobals. If you want to set a session var equal to an array, it doesn't make any difference..just say:

$_SESSION['myarray']=$myarray;