在keydown侦听函数JavaScript jQuery上绑定事件处理程序

Question

I am trying to bind a handler to an event. The event is a keydown function. The handler will listen for hit variables to produce one of two conditions. The 1st condition (odd number of hits) will perform 1 function, the 2nd (even number of hits) will perform another function. To elaborate, the 1st function will scroll to one element, the 2nd will scroll to another element

FIDDLE

Above is a link to a demo, there is a nasty bug which you can see.

The only thing I can think of is that the following should be revised for the second event:

.offset().top

Answer 1

在keydown函数外部声明hits因此不会每次都重置为0。

Answer 2

No, not the condition is in the wrong place but your variable declaration and initialisation. If you do

hits = 0;
if (hits % 2 !== 0) …

the condition will obviously be always false.

Move the declaration outside the scope of your event handler function, and don't reset it each time right before you query it.