array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'zh', ), 'this' => array ( 0 => 'hash.constants.php', 1 => '预定义常量', 2 => '预定义常量', ), 'up' => array ( 0 => 'book.hash.php', 1 => 'Hash', ), 'prev' => array ( 0 => 'hash.resources.php', 1 => '资源类型', ), 'next' => array ( 0 => 'class.hashcontext.php', 1 => 'HashContext', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'zh', 'path' => 'reference/hash/constants.xml', ), 'history' => array ( ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); contributors($setup); ?>

预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

HASH_HMAC (int): hash_init() 中的可选标志。表示 HMAC digest-keying 算法应被用于当前散列上下文环境。