In HTML, Radio choice buttons allow developers to create multiple options for a selection. The user can select any option and we can get its value and know which option the user selected among multiple options.
Therefore, it is important to check which radio button the user selected to understand their choice from multiple options. Let us understand it through real life examples. When you fill any form and ask to choose gender, you can see they give you three options and you can choose only one.
In this tutorial, we will learn two ways to check if a radio button is selected using JavaScript.
Use the checked attribute of the radio button
We can access the radio element in JavaScript using various methods. After that we can check if the selected radio button is checked or not using its checked property. If the value of the checked attribute is true, it means that the radio button is selected; otherwise, it is not selected.
grammar
Users can check whether the radio button is checked using the checked attribute of the radio element according to the following syntax.
<input type = "radio" name = "radio" value = "male" id = "radio1" > Male</input>
<script>
let radio1 = document.getElementById('radio1');
if(radio1.checked){
// radio1 is checked
}
</script>
In the above syntax, we access the radio button using its id and use the checked attribute to check if the radio button is selected in the if statement.
Example
In the example below, we have created three radio buttons containing different values, such as male, female, etc. In JavaScript, we access each radio button by its ID and check the value of each radio button's "checked" attribute.
When the user selects any radio button and clicks on it, they will see a message showing the value of the selected radio button.
<html>
<body>
<h3 id="Using-the-i-checked-property-i-of-the-radio-button-to-check-whether-a-radio-button-is-selected">Using the <i>checked property</i> of the radio button to check whether a radio button is selected.</h3>
<input type = "radio" name = "radio" value = "male" id = "radio1" > Male </input> <br>
<input type = "radio" name = "radio" value = "female" id = "radio2" > Female </input><br>
<input type = "radio" name = "radio" value = "other" id = "radio3" /> Other </input>
<p id = "output"> </p>
<button onclick = "checkRadio()"> Check radio </button>
<script>
let output = document.getElementById("output");
function checkRadio(){
// accessing the radio buttons
let radio1 = document.getElementById('radio1');
let radio2 = document.getElementById('radio2');
let radio3 = document.getElementById('radio3');
// checking if any radio button is selected
if(radio1.checked){
output.innerHTML = "The radio button with value " + radio1.value + " is checked!";
}
if(radio2.checked){
output.innerHTML = "The radio button with value " + radio2.value + " is checked!";
}
if(radio3.checked){
output.innerHTML = "The radio button with value " + radio3.value + " is checked!";
}
}
</script>
</body>
</html>
Example
The example below is almost the same as the one above, except that we access all the radio buttons at once using their names. The getElementByName() method returns all radio elements named radio.
After that, we use a for-of loop to loop through the radio button array and check if each radio button is checked using the "checked" attribute.
<html>
<body>
<h3 id="Using-the-i-checked-property-i-of-the-radio-button-to-check-whether-a-radio-button-is-selected">Using the <i>checked property</i> of the radio button to check whether a radio button is selected</h3>
<input type = "radio" name = "radio" value = "10" id = "radio1"> 10 </input> <br>
<input type = "radio" name = "radio" value = "20" id = "radio2"> 20 </input> <br>
<input type = "radio" name = "radio" value = "30" id = "radio3" /> 30 </input>
<p id = "output"> </p>
<button onclick = "getSelectedRadio()"> Check radio </button>
<script>
let output = document.getElementById("output");
function getSelectedRadio() {
let radioButtons = document.getElementsByName('radio');
for (let radio of radioButtons) {
if (radio.checked) {
output.innerHTML = "The radio button is selected and it's value is " + radio.value;
}
}
}
</script>
</body>
</html>
Use querySelector() method to check whether the radio button is selected
Programmers can use JavaScript's querySelector() method to select any HTML element. Here we use querySelector() method to select only the selected radio buttons. If the radio button is not selected, a null value is returned.
grammar
Users can use the querySelector() method according to the following syntax to check whether the radio button is selected.
var selected = document.querySelector('input[name="year"]:checked');
In the above syntax, "year" is the name of the radio button group, and it returns any radio button that belongs to the "year" group and is selected.
Example
In the example below, we have created three radio buttons to provide the user with three different choices. When the user clicks the "Check Selected Year" button, it calls the getSelectedRadio() function, which selects the radio button named "year" using the querySelector() method and checks it from the DOM.
The user can click the button and observe the output without selecting any radio button.
<html>
<body>
<h3 id="Using-the-i-querySelector-method-i-to-check-whether-a-radio-button-is-selected">Using the <i> querySelector() method </i> to check whether a radio button is selected.</h3>
<input type = "radio" name = "year" value = "1999" id = "radio1"> 1999 </input><br>
<input type = "radio" name = "year" value = "2021" id = "radio2"> 2021 </input><br>
<input type = "radio" name = "year" value = "2001" id = "radio3" /> 2001 </input>
<p id="output"></p>
<button onclick="getSelectedRadio()">Check selected year</button>
<script>
let output = document.getElementById("output");
function getSelectedRadio() {
var selected = document.querySelector(
'input[name="year"]:checked');
if (selected) {
output.innerHTML += "Radio button is selected."
} else {
output.innerHTML += "Not any radio button is selected!"
}
}
</script>
</body>
</html>
Users learned two different ways to get the selected radio button using JavaScript. The best way is to use querySelector() method as we only need to write one line of code.
The above is the detailed content of How to check if a radio button is selected using JavaScript?. For more information, please follow other related articles on the PHP Chinese website!
From Websites to Apps: The Diverse Applications of JavaScriptApr 22, 2025 am 12:02 AMJavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.
Python vs. JavaScript: Use Cases and Applications ComparedApr 21, 2025 am 12:01 AMPython is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.
The Role of C/C in JavaScript Interpreters and CompilersApr 20, 2025 am 12:01 AMC and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.
JavaScript in Action: Real-World Examples and ProjectsApr 19, 2025 am 12:13 AMJavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.
JavaScript and the Web: Core Functionality and Use CasesApr 18, 2025 am 12:19 AMThe main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.
Understanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AMUnderstanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.
Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AMPython is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AMPython and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
SublimeText3 English version
Recommended: Win version, supports code prompts!
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
SublimeText3 Mac version
God-level code editing software (SublimeText3)
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
Atom editor mac version download
The most popular open source editor
