How to get all elements in javascript

JavaScript HTML DOM Elements

This page teaches you how to find and access HTML elements in an HTML page.

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

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

elements:

Example

This example finds the element with id=»main» , and then finds all

elements inside «main» :

Example

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

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

elements with class=»intro» .

Example

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 + "
«;
>
document.getElementById(«demo»).innerHTML = text;

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

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How to find and get HTML Elements in JavaScript

The getElementById() method is the most straightforward way to locate an HTML element in the DOM. The getElementById() method returns an element with the value specified. Because an element’s id is unique within an HTML document, the document.getElementById() is a fast way to get to an element.

This example looks for the element with the id=»intro» :

const element = document.getElementById("intro"); 

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

The getElementsByTagName() method returns a collection of all elements with a specified tag name.

This example finds all

elements:

const element = document.getElementsByTagName("p"); 

Finding HTML Elements by Class Name

Use getElementsByClassName() to find all HTML elements with the same class name.
This example returns a list of all elements that have the class=»intro» attribute.

const x = document.getElementsByClassName("intro"); 

Finding HTML Elements by Name

The getElementsByName() method returns the elements that match the value of the name attribute with the passed string.

document.getElementByName("first-name"); 

Finding HTML Elements using querySelector

The querySelector method returns the first element that matches the passed selector.

// using id selector document.querySelector("#parent"); // using class selector document.querySelector(".myclass"); //Returns first element in the document with class name // using tagname document.querySelector("p"); //Returns the first p element // using tagname document.querySelector("div span.child"); //Returns first span element with class name child, inside a div 

Finding HTML Elements using querySelectorAll

The querySelectorAll method is an extension of the querySelector method. Use the querySelectorAll() method to find all HTML elements that match a specified CSS selector (id, class names, types, attributes, attribute values, and so on).

This example returns a list of all elements that have the class=“subheading” attribute.

const x = document.querySelectorAll("h2.subheading"); 

Conclusion

The most common JavaScript methods for finding and retrieving elements in a JavaScript program are:

• getElementById()
• getElementsByTagName()
• getElementsByClassName()
• and querySelectorAll()

You can use any of the methods listed above to find a specific HTML element in the code. This article discussed how to find and retrieve HTML elements in JavaScript.

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How to get DOM elements using JavaScript

The Document Object Model (DOM) is a programming interface for HTML and XML documents created by the browser once the document is loaded. A web page is a document represented by the DOM as nodes and objects. It allows programs to manipulate the document’s content, structure, and styles.

In this tutorial, we shall learn how to use JavaScript to access different nodes (HTML elements) in the DOM. Let us start with the first method: getting an element by ID.

The document ‘s getElementById() method takes the element ID as input and returns an Element object representing the DOM element. Here is an example:

const unicorn = document.getElementById('unicorn') 

The ID is case-sensitive and unique across the entire HTML document. So this method always returns a single element. If no matching element is found, it returns null .

Note: Do not put the # sign before the ID string while calling getElementById() method. You will get null instead of the element, and then you might wonder for hours what has gone wrong.

The getElementsByTagName() method is used to access multiple elements. It takes the tag name as input and returns all of the DOM elements that match the tag name as HTMLCollection :

JavaScript code to access all

elements:

const animals = document.getElementsByTagName('p') 

This method searches only one tag name at a time. But if you pass in * as the tag name, you will get all elements in the DOM:

const allNodes = document.getElementsByTagName('*') 

The getElementsByName() method is used to get a collection of elements by their name attribute and returns a NodeList object:

input type="text" name="email"> input type="tel" name="phone"> input type="date" name="dob"> 

const emails = document.getElementsByName('email') 

Note: Unlike the id attribute, which must be unique, multiple HTML elements can have the same name attribute. That’s why getElementsByName() returns a collection of nodes.

Want to use the class attribute to get a list of matching elements? You can use the getElementsByClassName() method, pass it a class name (without . ), and it will return an HTMLCollection of all DOM elements that have the given class name:

div class="bird owl">🦉div> div class="bird">🐦div> div class="bird eagle">🦅div> div class="animal cat">🐱div> 

const birds = document.getElementsByClassName('bird') 

This method also accepts multiple class names separated by spaces. Let us get all elements that have both the bird and eagle classes:

const eagle = document.getElementsByClassName('bird eagle') 

The querySelector() method is one of the two modern JavaScript methods that allow you to get elements from DOM based on CSS selectors. Just pass in the CSS selector, and you will get the first element that matches the specified selector. If no matches exist, it returns null . Here is an example:

const email = document.querySelector('#signup input[name="email"]') 

Want to select a list of elements that match the specified selectors? Use the querySelectorAll() method instead. This method takes multiple CSS selectors as input and returns a NodeList , a list of DOM elements that match the given selectors. Let us select all elements with a class of either bird or animal from the above HTML markup:

const elems = document.querySelectorAll('.bird, .animal') console.log(elems.length) // 4 

You can also chain multiple functions together to search elements within another element. You first need to select a single element using either getElementById() or querySelector() and then chain another function to search within:

form id="signup"> input type="text" name="email"> input type="tel" name="phone"> input type="date" name="date-of-birth"> form> 

const inputs = document.getElementById('signup').getElementsByTagName('input') // OR const inputs = document.querySelector('#signup').querySelectorAll('input') 

Most of the methods we discussed above (except getElementById() and querySelector() ) returns multiple elements as either an HTMLCollection or a NodeList . The HTMLCollection is not an array but a generic collection of elements. So it is impossible to iterate over it with the forEach() or map() method. However, we can convert it to a real array and then iterate using the Array.from() method:

const inputs = document.getElementById('signup').getElementsByTagName('input') // iterate over HTMLCollection Array.from(inputs).forEach(element =>  console.log(element) >) 

Although NodeList is also not an array, it does provide the forEach() method to iterate over the elements:

const inputs = document.querySelector('#signup').querySelectorAll('input') //iterate over NodeList inputs.forEach(element =>  console.log(element) >) 

That’s all for getting DOM elements using JavaScript. We have learned about many different methods to access the DOM elements: using the id attribute, HTML tag name, name attribute, class attribute, and CSS selectors. We also discussed ways to iterate over the generic collection of elements returned by these methods. ✌️ Like this article? Follow me on Twitter and LinkedIn. You can also subscribe to RSS Feed.

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