How to solve the problem of javascript

In JavaScript, methods for using DOM to process HTML document elements include: obtaining elements (such as getElementById, getElementsByTagName, querySelector), operating elements (such as innerHTML, outerHTML, textContent), and creating new elements (such as createElement, createTextNode ), attaching or removing elements (such as appendChild, insertBefore, removeChild) and event handling (such as addEventListener, re

##How to handle DOM elements in JavaScript ?

Specific processing method:

1. Get the element

##getElementById(id)
• : Get a single element based on its id attribute. ##getElementsByTagName(tagName): Get the set of all matching elements based on the tag name of the element
• getElementsByClassName(className): Get the set of all matching elements based on the class name of the element. .
• querySelector(selector): Use CSS selector to get the first matched element.
• querySelectorAll(selector): Use CSS to select. Gets a collection of all matching elements
• 2. Operate elements

innerHTML: Get or set the inner content of the element. Linked HTML.

##outerHTML
• : Get or set the complete HTML of the element, including itself. ##textContent
: Get or set the text content of the element. Does not contain child elements.
• value
: Gets or sets the value of a form element (such as a text box or drop-down list)
• style
: Gets. Or set the style attribute of the element to support inline styles
• ##3. Create a new element
• ##createElement(tagName)
: Create a new HTML element.

createTextNode(text): Create a new text node.

• 4. Append or remove elements
• appendChild(child)
: Add child elements to the parent element end.

insertBefore(newChild, refChild): Insert the new child element before the specified child element.

• removeChild(child): Remove the specified child element from the parent element.
• 5. Event handling
• addEventListener(type, handler)
: Add an event listener to the element.

removeEventListener(type, handler): Remove an event listener.

• Example:

<code class="javascript">// 获取元素
const element = document.getElementById("my-element");

// 设置元素文本
element.textContent = "Hello World!";

// 添加事件监听器
element.addEventListener("click", function() {
  alert("Element clicked!");
});

// 创建新元素
const newElement = document.createElement("p");

// 设置新元素文本
newElement.textContent = "New element";

// 附加新元素
element.appendChild(newElement);</code>

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