# 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。

`YAF_VERSION` (string)
`YAF_ENVIRON` (string)
`YAF_ERR_STARTUP_FAILED` (int)
`YAF_ERR_ROUTE_FAILED` (int)
`YAF_ERR_DISPATCH_FAILED` (int)
`YAF_ERR_AUTOLOAD_FAILED` (int)
`YAF_ERR_NOTFOUND_MODULE` (int)
`YAF_ERR_NOTFOUND_CONTROLLER` (int)
`YAF_ERR_NOTFOUND_ACTION` (int)
`YAF_ERR_NOTFOUND_VIEW` (int)
`YAF_ERR_CALL_FAILED` (int)
`YAF_ERR_TYPE_ERROR` (int)

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