添加链接
link管理
链接快照平台
  • 输入网页链接,自动生成快照
  • 标签化管理网页链接

Finding HTML Elements

Often, with JavaScript, you want to manipulate HTML elements.

To do so, you have to find the elements first. There are several ways to do this:

  • Finding HTML elements by id
  • Finding HTML elements by tag name
  • Finding HTML elements by class name
  • Finding HTML elements by CSS selectors
  • Finding HTML elements by HTML object collections
  • Finding HTML Element by Id

    The easiest way to find an HTML element in the DOM, is by using the element id.

    This example finds the element with id="intro" :

    Example

    const element = document.getElementById("intro"); Try it Yourself »

    If the element is found, the method will return the element as an object (in element).

    If the element is not found, element will contain null .

    Finding HTML Elements by Tag Name

    This example finds all <p> elements:

    Example

    const element = document.getElementsByTagName("p"); Try it Yourself »

    This example finds the element with id="main" , and then finds all <p> elements inside "main" :

    Example

    const x = document.getElementById("main");
    const y = x.getElementsByTagName("p"); Try it Yourself »

    Finding HTML Elements by Class Name

    If you want to find all HTML elements with the same class name, use getElementsByClassName() .

    This example returns a list of all elements with class="intro" .

    Example

    const x = document.getElementsByClassName("intro"); Try it Yourself »

    Finding HTML Elements by CSS Selectors

    If you want to find all HTML elements that match a specified CSS selector (id, class names, types, attributes, values of attributes, etc), use the querySelectorAll() method.

    This example returns a list of all <p> elements with class="intro" .

    Example

    const x = document.querySelectorAll("p.intro"); Try it Yourself »

    Finding HTML Elements by HTML Object Collections

    This example finds the form element with id="frm1" , in the forms collection, and displays all element values:

    Example

    const x = document.forms["frm1"];
    let text = "";
    for (let i = 0; i < x.length; i++) {
    text += x.elements[i].value + "<br>";
    }
    document.getElementById("demo").innerHTML = text; Try it Yourself »

    The following HTML objects (and object collections) are also accessible:

  • document.anchors
  • document.body
  • document.documentElement
  • document.embeds
  • document.forms
  • document.head
  • document.images
  • document.links
  • document.scripts
  • document.title
  • Exercise:

    Use the getElementById method to find the <p> element, and change its text to "Hello".

    <p id="demo"></p> <script> = "Hello"; </script>

    Start the Exercise

    Contact Sales

    If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
    [email protected]

    Report Error

    If you want to report an error, or if you want to make a suggestion, send us an e-mail:
    [email protected]

    W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. While using W3Schools, you agree to have read and accepted our terms of use , cookie and privacy policy .

    W3Schools is Powered by W3.CSS .