JS timeout for hover over an element

JS_setTimeout

  //Set timeout if hover over an element
  $(document).ready(function() {

  $('#slider').hover(
    // if hover over an element
    function(){
        setTimeout(function() {
            $('i.arrows').css({"opacity":"1"});
        }, 
        300); 
    },
    // if don't bring element
    function(){
        setTimeout(function() {
            $('i.arrows').css({"opacity":"0"});
        }, 
        500);
    });

  });