Element: focus event - Web APIs 编辑

The focus event fires when an element has received focus. The main difference between this event and focusin is that focusin bubbles while focus does not.

The opposite of focus is blur.

Examples

Simple example

HTML

<form id="form">
  <input type="text" placeholder="text input">
  <input type="password" placeholder="password">
</form>

JavaScript

const password = document.querySelector('input[type="password"]');

password.addEventListener('focus', (event) => {
  event.target.style.background = 'pink';
});

password.addEventListener('blur', (event) => {
  event.target.style.background = '';
});

Result

Event delegation

There are two ways of implementing event delegation for this event: by using the focusin event, or by setting the useCapture parameter of addEventListener() to true.

HTML

<form id="form">
  <input type="text" placeholder="text input">
  <input type="password" placeholder="password">
</form>

JavaScript

const form = document.getElementById('form');

form.addEventListener('focus', (event) => {
  event.target.style.background = 'pink';
}, true);

form.addEventListener('blur', (event) => {
  event.target.style.background = '';
}, true);

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Related events: blur, focusin, focusout
• This event on Window targets: focus event