Php how to include in a variable name another variable - php

Question

In the example are two arrays, but actually may be other number of arrays (i do not know how many arrays i may have).
$some_name = array ( "Volvo_0",220,180, );
$array_name_for_variable[]='some_name';//here i create another array latter to loop through
$another_name = array ( "Volvo_1",221,181, );
$array_name_for_variable[]='another_name';
In the example i just want to print_r the arrays i may have. So i loop through $array_name_for_variable. Like
foreach( $array_name_for_variable as $i_array_name_for_variable => $val_array_name_for_variable ) {
trying to print particular array (like print_r($some_name)), using this
echo '<pre>', print_r($['val_array_name_for_variable'], true), '</pre> $val_array_name_for_variable __<br/>';
but see error Parse error: syntax error, unexpected '[', expecting T_VARIABLE or '$'
}
This print_r($['val_array_name_for_variable']) is wrong. Tried this print_r( $[$val_array_name_for_variable] );. Also got error.
Any ideas what need to change.
Why all this and what i need...
I have 12 arrays, but i do not know which of 12 would be used in one particular page.
So page loads, some of the 12 arrays are defined (used).
I may write like if array_1 exists, then long html code using variables from the array_1.
Then again if array_2 exists and not empty, then repeat the same html code with variables from array_2.
But instead of copy-paste (repeating) html code i decided to loop through arrays existing in opened page and the long html code write only once.

Answer 1

You could solve the problem with:
$some_name = array ( "Volvo_0",220,180, );
$array_name_for_variable[]=$some_name;
$another_name = array ( "Volvo_1",221,181, );
$array_name_for_variable[]=$another_name;
then iterate through it:
foreach( $array_name_for_variable as $i_array_name_for_variable => $val_array_name_for_variable ) {
echo '<pre>', print_r($val_array_name_for_variable, true), '</pre><br/>';
}
This will print all the elements in $array_name_for_variable.
Comment if you need any more changes to the output.
Explanation: What the code is actually doing is iterating through all elements of the array $array_name_for_variable. They it creates a key => value for each element in it. The value ($val_array_name_for_variable) on the first iteration would be: $some_name. The key ($i_array_name_for_variable) - the element position in the array, so on the first iteration it would be 0 (as it always start from 0).
If you don't need the element position you could do it like this:
foreach( $array_name_for_variable as $val_array_name_for_variable ) {
echo '<pre>', print_r($val_array_name_for_variable, true), '</pre><br/>';
}
It would generate exactly the same output as the previous code snippet.
For adding elements to the array you have to pass a variable and you were passing just a string.
EDIT:
Based on the newly added info the code should be:
foreach( $array_name_for_variable as $i_array_name_for_variable => $val_array_name_for_variable ) {
if (array_key_exists($i_array_name_for_variable, $val_array_name_for_variable)) {
echo '<pre>', print_r($val_array_name_for_variable, true), '</pre><br/>';
} else {
//Code if the array does not exist.
}
}
References:
http://php.net/manual/en/control-structures.foreach.php
http://php.net/manual/en/function.array-push.php
http://php.net/manual/en/function.array-key-exists.php

Answer 2

You may want to do something like this
$some_name = array ( "Volvo_0",220,180, );
$array_name_for_variable['some_name']= $some_name ;
$another_name = array ( "Volvo_1",221,181, );
$array_name_for_variable['another_name']= $another_name ;
foreach( $array_name_for_variable as $i_array_name_for_variable => $val_array_name_for_variable ) {
print_r($val_array_name_for_variable);//prints the array
print_r($i_array_name_for_variable);// print the keys ex :- some_name
}