Done

01/app.js

@@ -1 +1,11 @@
-console.log('DOM');
+
+const liElement = document.querySelector('.comments__item.comments__item--newest');
+const dataInfoList = liElement.querySelectorAll('[data-info]');
+
+if(liElement && dataInfoList) {
+    console.log(`Znaleziono ${dataInfoList.length} poniższe elementy z atrybutem  data-info :`);
+
+    dataInfoList.forEach(function(element) {
+        console.log(element)
+    });
+}

02/app.js

@@ -1 +1,10 @@
-console.log('DOM');
+const linkList = document.querySelectorAll('[data-url')
+
+linkList.forEach(function(link) {
+    const url = link.getAttribute('data-url');
+
+    if(url) {
+        link.setAttribute('href', url)
+    }
+});
+

03/app.js

@@ -11,4 +11,20 @@ const buttonSettings = {
         color: '#444'
     },
     text: 'Click me!',
+}
+
+const button = document.createElement('button');
+
+for (const attr in buttonSettings.attr) {
+    button[attr] = buttonSettings.attr[attr];
+}
+for (const style in buttonSettings.css) {
+    button.style[style] = buttonSettings.css[style];
+}
+
+button.textContent = buttonSettings.text;
+
+const parentButton = document.querySelector('.parent-for-button');
+if (parentButton) {
+    parentButton.appendChild(button);
 }

04/app.js

@@ -1,8 +1,24 @@
-console.log('DOM');
 
 // struktura do wykorzystania w pętli
 const menuItems = [
     {text: 'start', url: '/'},
     {text: 'galeria', url: '/gallery'},
     {text: 'kontakt', url: '/contact'},
-];
+];
+
+const nav = document.querySelector('nav');
+const ul = document.createElement('ul');
+
+
+
+menuItems.forEach(function(item) {
+    const li = document.createElement('li');
+    const a = document.createElement('a');
+    a.href = item.url;    
+    a.textContent = item.text;
+
+    li.appendChild(a);
+    ul.appendChild(li);
+});
+
+nav.appendChild(ul);

05/app.js

@@ -1,3 +1,45 @@
-console.log('DOM');
-
 const curr = document.querySelector('.js-curr');
+
+// 
+const newButton = document.createElement('button');
+newButton.classList.add('article__btn');
+newButton.textContent = 'usuń z koszyka'
+
+curr.parentElement.insertBefore(newButton, curr.nextElementSibling);
+
+
+// 
+let sibling = curr.parentElement.firstElementChild;
+while (sibling) {
+  if (sibling !== curr) {
+    sibling.classList.add('siblings');
+  }
+  sibling = sibling.nextElementSibling;
+}
+
+
+// 
+const nextArticle = curr.closest('.article').nextElementSibling;
+if(nextArticle && nextArticle.classList.contains('article')) {
+    nextArticle.setAttribute('title', 'nextElementSibling');
+}
+
+
+// 
+const lastArticle = document.querySelector('.articles__item:last-child');
+const paragraph = document.createElement('p');
+paragraph.textContent = 'Dodskowy paragraf.';
+const button = lastArticle.querySelector('.article__btn');
+lastArticle.insertBefore(paragraph, button);
+
+// 
+const newArticle = document.createElement('article');
+newArticle.classList.add('articles__item', 'article');
+const articlesSection = document.querySelector('.articles');
+articlesSection.insertBefore(newArticle, articlesSection.firstElementChild);
+
+newArticle.innerHTML = `
+  <h1 class="article__title">JS- Nowy Artykuł</h1>
+  <p class="article__description">Lorem ipsum dolor sit amet consectetur adipisicing elit. Consequatur quo quibusdam, nemo neque consequuntur pariatur totam? Facere quaerat molestias hic.</p>
+  <button class="article__btn">Kupuję!</button>
+`;