1$( "div.enterleave" )
2  .mouseenter(function() {
3    n += 1;
4    $( this ).find( "span" ).text( "mouse enter x " + n );
5  })
6  .mouseleave(function() {
7    $( this ).find( "span" ).text( "mouse leave" );
8  });

1$("#id").mouseover();

1let test = document.getElementById("test");
2  
3// This handler will be executed only once when the cursor
4// moves over the unordered list
5test.addEventListener("mouseenter", function( event ) {   
6  // highlight the mouseenter target
7  event.target.style.color = "purple";
8
9  // reset the color after a short delay
10  setTimeout(function() {
11    event.target.style.color = "";
12  }, 500);
13}, false);