javascript - jquery :: Why does hover trigger instantly?

Question

Why does the hover event trigger as soon as the page is loaded?

function showSelector(position) {
  alert(position);
}

function hideSelector() {
}

$("#1").hover(showSelector(17), hideSelector);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<a href="" id="1">sup</a>

Answer 1

Because you are invoking the function by adding () at the end, what you can do is to pass a anonymous function as the mouseenter callback which can call showSelector with the desired arguments like

function showSelector(position) {
  alert(position);
}

function hideSelector() {}

$("#1").hover(function() {
  showSelector(17)
}, hideSelector);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<a href="" id="1">sup</a>