不能声明 class 常量或 属性 变量

Can't declare class constant nor property variable

class Model {

  public $DATABASE_NAME = 'dealer-kunde-skuska';

       // OR

  const DATABASE_NAME = 'dealer-kunde-skuska';

}

None 以上声明有效。它returns错误:

Parse error: parse error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' in ... on line 5

有什么问题吗?

publicconst 仅适用于 PHP 5。var 用于 PHP 4.

Support for PHP 4 has been discontinued since 2007-12-31. Please consider upgrading to PHP 5.

也许升级? PHP 5 已推出 11 年,PHP 4 已停产 7。