php - 使用变量名获取常量值

Question

我有一个像下面这样的类(class)，

 namespace DTS\eBaySDK\Constants;
 class SiteIds
{
    // United States
    const US = 0;
    // Canada (English)
    const ENCA = 2;
    // UK
    const GB = 3;
    // Australia
    const AU = 15;
    // Austria
    const AT = 16;
    // Belgium (French)
    const FRBE = 23;
    // France
    const FR = 71;
    // Germany
    const DE = 77;
    // Motors
    const MOTORS = 100;
    // Italy
    const IT = 101;
    // Belgium (Dutch)
    const NLBE = 123;
    // Netherlands
    const NL = 146;
    // Spain
    const ES = 186;
    // Switzerland
    const CH = 193;
    // Hong Kong
    const HK = 201;
    // India
    const IN = 203;
    // Ireland
    const IE = 205;
    // Malaysia
    const MY = 207;
    // Canada (French)
    const FRCA = 210;
    // Philippones
    const PH = 211;
    // Poland
    const PL = 212;
    // Singapore
    const SG = 216;
}

我可以按如下方式访问它，

echo Constants\SiteIds::US;

但是当我尝试像下面这样访问它时，它不起作用，

  $country ='US';
  echo Constants\SiteIds::$country;

有没有办法像这样访问？

Answer 1

试试这个代码:

$ref = new ReflectionClass('DTS\eBaySDK\Constants\SiteIds');
$constName = 'US';
echo $ref->getConstant($constName);

我在以下位置找到了这个答案: stackoverflow.com