PHP Variable Variables within setter function - php

Question

I am trying to achieve a way to define an indefinite, but not infinite number of variables, to be used to create objects. I have tried a couple of ways to try this but i cant seem to wrap my head around this.
Here is what i came up with:
$aCount= 0;
$Foo = "Bar".$aCount;
$$Foo = array("Data1"=>NULL, "Data2"=>NULL);
function getBarData1() {
return ${$Foo}['Data1'];
}
function getBarData2() {
return ${$Foo}['Data2'];
}
function setBarData($newBarData1, $newBarData2) {
${$Foo}['Data1'] = $newBarData1;
${$Foo}['CONTENT'] = $newBarData2;
$aCount++;
}
setBarData('First', 'Line');
setBarData('Second', 'Dot');
setBarData('Third', 'Dash');
for($aCount == $aCount; $aCount > -1; $aCount--) {
echo getBarData1() ."\n";
echo getBarData2() ."\n";
}
Any help would be greatly appreciated.

Answer 1

You are heading two problems:
variable scope
value of variable $Foo is static and never change - value is always: Bar0 even when you change $aCount because the value is just a string
working example:
<?php
$aCount= 0;
$Foo = function(){ global $aCount; return "Bar".$aCount; };
${$Foo()} = array("Data1"=>NULL, "Data2"=>NULL);
function getBarData1() {
global $Foo, ${$Foo()};
return ${$Foo()}['Data1'];
}
function getBarData2() {
global $Foo, ${$Foo()};
return ${$Foo()}['Data2'];
}
function setBarData($newBarData1, $newBarData2) {
global $aCount, $Foo, ${$Foo()};
${$Foo()}['Data1'] = $newBarData1;
${$Foo()}['Data2'] = $newBarData2;
$aCount++;
}
setBarData('First', 'Line');
setBarData('Second', 'Dot');
setBarData('Third', 'Dash');
$aCountTotal = $aCount;
for($i = 0; $i < $aCountTotal; $i++) {
$aCount = $i;
echo getBarData1() ."\n";
echo getBarData2() ."\n";
}
in this case you should use array instead, variable-variable is really usefull in rare cases
array example:
<?php
$arr = array();
function getBarData1($index) {
global $arr;
return $arr[$index]['Data1'];
}
function getBarData2($index) {
global $arr;
return $arr[$index]['Data2'];
}
function setBarData($newBarData1, $newBarData2) {
global $arr;
$arr[] = ['Data1' => $newBarData1, 'Data2' => $newBarData2];
}
setBarData('First', 'Line');
setBarData('Second', 'Dot');
setBarData('Third', 'Dash');
for($i = 0; $i < count($arr); $i++) {
echo getBarData1($i) ."\n";
echo getBarData2($i) ."\n";
}
better than using global variable in functions is passing data through parameters like:
<?php
$arr = array();
function getData1($array, $index) {
return $array[$index]['Data1'];
}
function getData2($array, $index) {
return $array[$index]['Data2'];
}
// reference to $array because we want to change the value
function setData(&$array, $newBarData1, $newBarData2) {
$array[] = ['Data1' => $newBarData1, 'Data2' => $newBarData2];
}
setData($arr, 'First', 'Line');
setData($arr, 'Second', 'Dot');
setData($arr, 'Third', 'Dash');
for($i = 0; $i < count($arr); $i++) {
echo getData1($arr, $i) ."\n";
echo getData2($arr, $i) ."\n";
}