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JavaScript - Checkbox change event


A simple code example introducing how to implement a checkbox change event using addEventListener() in JavaScript.

The HTML has checkboxes with class "checkbox" to detect value changes.

<div class="item-container">
	<p id="output">Please check your favorite.</p>
	<div class="checkboxs">
		<p><input type="checkbox" id="checkbox-a" class="checkbox" name="name" value="A">
		<label for="checkbox-a">A</label></p>
		<p><input type="checkbox" id="checkbox-b" class="checkbox" name="name" value="B">
		<label for="checkbox-b">B</label></p>
		<p><input type="checkbox" id="checkbox-c" class="checkbox" name="name" value="C">
		<label for="checkbox-c">C</label></p>

The target checkboxes are queried with querySelectorAll() and addEventListener() is used on each to implement a "change" event to get the changed values.

The code example displays the values and checked status in the output area when checkboxes change.

// Get all target checkboxes
let checkboxs = document.querySelectorAll('.checkbox');

// Add change event to each checkbox
for (let target of checkboxs) {
	target.addEventListener(`change`, () => {
		// Display result in output area 
		document.querySelector(`#output`).innerHTML = `${target.value}:${target.checked}`;

JavaScript - Checkbox change event

TitleJavaScript - Checkbox change event