Php Preg请输入json多维字符串

我有这样的字符串：

<?php
echo $str_is;
?>

$thearray["id_is"]="'bG1saW50YXMgbWFoYWthbTMyMTI'"
$thearray["date_is"]="'2015-2-25'"

我需要得到如下数组：

<?php
echo $str_is;
?>

$thearray["id_is"]="'bG1saW50YXMgbWFoYWthbTMyMTI'"
$thearray["date_is"]="'2015-2-25'"

我尝试使用（im新手使用代码preg_match）：

---

这将是一种方法：

$str_is = <<< EOS
[["id_is","'bG1saW50YXMgbWFoYWthbTMyMTI'"],["date_is","'2015-2-25'"]]
EOS;

// Convert the JSON string to an array
$array = json_decode($str_is, true);

// Loop the array adding to $thearray
foreach ($array as $pair) {
   // First element = key (e.g. "id_is")
   // Second element = value (e.g. "'bG1saW50YXMgbWFoYWthbTMyMTI'")
    $thearray[$pair[0]] = $pair[1];
}

echo $thearray['id_is'], PHP_EOL;
echo $thearray['date_is'], PHP_EOL;

'bG1saW50YXMgbWFoYWthbTMyMTI'
'2015-2-25'