PHP变量获取数组值

Question

I'm building a condition check where I'm passing in the variable and a value to check. In this case the variable is an array value, but I can't get it to return it correctly

//happens somewhere else
$specialFeature['option1']="on";
$specialFeature['option2']="on";
$specialFeature['option3']="off";

//what I'm trying to do
#query a db
$row = $result->fetch_array()
#results for purpose of demo
#$row['var'] = "specialFeature['option2']";
#$row['val'] = "on";
if($$row['var'] == $row['val']){
    //what i'm expecting
    echo "OK";
}

My issue is $$var is always null. What am I doing wrong? Is this possible?

Answer 1

I'm not sure if what I'm doing is "correct", but I got the result I was looking for by doing this:

//happens somewhere else
$specialFeature['option1']="on";
$specialFeature['option2']="on";
$specialFeature['option3']="off";

//what I'm trying to do
#query a db
$row = $result->fetch_array()
#results for purpose of demo
#$row['var'] = "specialFeature['option2']";
#$row['val'] = "on";

$var = $row['var'];

if (strpos($var,'[') !== false) {
    $varA = str_split($var,strpos($var,'['));
    $varA[1] = substr($varA[1],1,-1);
    if (strpos($varA[1],"'") !== false) {
        $varA[1] = substr($varA[1],1,-1);
    }
}

if(${$varA[0]}[$varA[1]] == $row['val']){
    //what i'm expecting
    echo "OK";
}