We don't need to pass in the-string to recurse because it is already in the parent environment and does not change from call to call.

我们不必将the - string传递给recurse，因为它已经在父环境(parent environment)中，而且从一个调用到另一个调用时不会改变。

youdao

We don't need to pass in the-string to recurse because it is already in the parent environment and does not change from call to call.

我们不必将the - string传递给recurse，因为它已经在父环境(parent environment)中，而且从一个调用到另一个调用时不会改变。

youdao