170711_PracticeJS.md

1번

var node = document.createElement('li');
var textNode = document.createTextNode('watermellon');
node.appendChild(textNode);
document.querySelector('ul').insertBefore(node, null);

2번

var node = document.createElement("li");
var textNode = document.createTextNode("Watermellon");
node.appendChild(textNode);
var ul = document.querySelector('ul');
ul.insertBefore(node, document.querySelector('li:nth-child(3)'));

3번

var node = document.createElement("li");
var textNode = document.createTextNode("Watermellon");
node.appendChild(textNode);
var li = document.querySelector('li:nth-child(1)');
var ul = document.querySelector('ul');
ul.insertBefore(li, document.querySelector('li:nth-child(5)'));

4번

document.querySelectorAll('li.red')
  .forEach(element => {
    element.parentElement.removeChild(element)
});

[].slice.call(document.getElementsByClassName('red')).forEach(el => {
  el.parentElement.removeChild(el);
});

var elements = document.getElementsByClassName('red')
for (let i = elements.length - 1; i >= 0; i--) {
  elements[i].parentElement.removeChild(elements[i]);
}

5번

document.querySelectorAll('section').forEach(el => {
  if (el.querySelector('.blue') != null)
    el.removeChild(el.querySelector('h2'));
});