Answers for "hover in javascript css"

hover event javascript

element.addEventListener('mouseover',someFunction);

style hover js

<div id="mydiv">foo</div>

<script>
document.getElementById("mydiv").onmouseover = function() 
{
    this.style.backgroundColor = "blue";
}
</script>

hover con js

// Creamos el evento mouseover para cada imagen
	imagenes[i].addEventListener("mouseover", function(e){
		document.getElementById("mostrar").style.backgroundImage="url('"+e.target.currentSrc+"')";
	});
 
// Creamos el evento mouseout para cada imagen
imagenes[i].addEventListener("mouseout", function(e){
  document.getElementById("mostrar").style.backgroundImage="";
});