View difference between Paste ID: jhR0Rc69 and KyAJNmxz

 function solve() {
 
   const findTagFromParent = (parent, tag, text) => {
     const parents = document.getElementsByClassName(parent);
 
     for (parent of parents) {
       const descendants = parent.getElementsByTagName(tag);
       if (descendants.length) {
         const button = descendants[0];
         if (button.innerHTML === text) {
           return button;
         }
       }
     }
 
     return undefined;
   };
 
 
 
 
   const el = (tag, content, attributes) => {
     const element = document.createElement(tag);
     if (attributes) {
       //Ако са подадени атрибути (ID, className, etc.) ги закачаме към елемента
       Object.assign(element, attributes);
     }
     if (Array.isArray(content)) {
       //Ако създаваме например Div, в който трябва да има други елементи - p, span, etc., ги закачаме като масив
       content.forEach(appendEl);
     } else {
       //Ако не е масив, просто закачаме текста или числото, което сме подали
       appendEl(content);
     }
 
     function appendEl(node) {
       if (typeof node == "string" || typeof node == "number") {
         node = document.createTextNode(node);
       }
       element.appendChild(node);
     }
 
     return element;
   };
 
   const validateAndAdd = (e) => {
     const lectureName = document.getElementsByName("lecture-name")[0].value;
     const lectureDate = document.getElementsByName("lecture-date")[0].value;
     const lectureModule = document.getElementsByName("lecture-module")[0].value;
 
     if (
       lectureName === "" ||
       lectureDate === "" ||
       lectureModule === "Select module"
     )
       return;
 
     const title = `${lectureModule.toUpperCase()}-MODULE`;
 
     const chosenDate = new Date(lectureDate);
 
     gayFormatDate =
       chosenDate.getFullYear() +
       "/" +
       ("0" + chosenDate.getDate()).slice(-2) +
       "/" +
       ("0" + (chosenDate.getMonth() + 1)).slice(-2) +
       " - " +
       chosenDate.getHours() +
       ":" +
       ("0" + chosenDate.getMinutes()).slice(-2);
     const date = gayFormatDate;
 
     const module = findTagFromParent("module", "h3", title);
 
     const h4 = el("h4", `${lectureName} - ${date}`);
     const button = el("button", "Del", { className: "red" });
     const li = el("li", [h4, button], { className: "flex" });
 
     let ul;
 
     if (!module) {
       const modules = document.getElementsByClassName("modules")[0];
       const h3 = el("h3", title);
       ul = el("ul", li);
 
       const newModule = el("div", [h3, ul], { className: "module" });
       modules.appendChild(newModule);
     } else {
       ul = module.parentNode.getElementsByTagName("ul")[0];
 
       ul.appendChild(li);
     }
 
     e.preventDefault();
   };
 
 
   const addButton = findTagFromParent("form-control", "button", "Add");
 
   if (!addButton) {
     return;
   }
   addButton.addEventListener("click", validateAndAdd);
 
 
 
 }