PHP怎么实现输出数组变量？

$html['result'] = '1111111111';        
$arr = [
    'urls'=>"html['result']"
];
$temp = $arr['urls'];

$urls = $html['result'];
echo $$temp; // 输出 "1111111111"

$html['result'] = '1111111111';
$arr = [
    'urls' => "\$html['result']" 
];
$temp = $arr['urls'];

eval("\$temp = $temp;"); 

echo $temp; // 输出结果："1111111111"

$html['result'] = '1111111111';        
$arr = [
    'urls' => 'html',
];
$temp = null;

// 使用反射获取数组的值
$reflection = new ReflectionClass($arr['urls']);
$property = $reflection->getProperty('result');
$temp = $property->getValue($html);

echo $temp;

$html['result'] = '1111111111';        
$arr = [
    'urls'=>"html['result']"
];
$temp = $arr['urls'];

function getValue($str) {
    global $html;
    preg_match("/\['(.*)'\]/", $str, $matches);
    return $html[$matches[1]];
}

echo getValue($temp); // 输出 "1111111111"