function $A(iterable) { if (!iterable) return []; if ('toArray' in Object(iterable)) return iterable.toArray(); var length = iterable.length || 0, results = new Array(length); while (length--) results[length] = iterable[length]; return results; } window.onload = function() { $A(document.getElementsByTagName('p')).forEach(function(item, index) { if(item.innerHTML === "") { item.style.display = 'none'; } }); $A(document.getElementsByTagName('h1')).forEach(function(item, index) { var div = document.createElement('div'); div.setAttribute('class', 'arrow-down'); item.appendChild(div) }); } var toggle = function (element) { var next = element.nextElementSibling; var nextDisplay = next.style.display; next.style.display = nextDisplay != "block" ? "block" : "none"; if(element.classList.length === 0) { element.classList.add('abierto'); } else if(element.classList.contains('abierto')) { element.classList.remove('abierto'); element.classList.add('cerrado'); } else if(element.classList.contains('cerrado')) { element.classList.remove('cerrado'); element.classList.add('abierto'); } };