We didn't specify which function callback would be applied as the second argument, just that a function callback would be applied.

我们并没有指定哪个回调函数会被用作第二个参数，只需要是一个回调函数就可以了。

youdao

We didn't specify which function callback would be applied as the second argument, just that a function callback would be applied.

我们并没有指定哪个回调函数会被用作第二个参数，只需要是一个回调函数就可以了。

youdao