JavaScript keyup Event

The keyup event is a keyboard event that occurs when a user releases a key on their keyboard. This event is widely used for implementing real-time search features, form validation, and more.

Syntax

element.addEventListener('keyup', function(event) {
  // code to execute on keyup event
});

• element: The element to which the event listener should be attached.
• event: The event object that is passed as an argument to the event listener function.

Example

<input type="text" id="search-input">
<div id="search-results"></div>

const searchInput = document.getElementById('search-input');
const searchResults = document.getElementById('search-results');

searchInput.addEventListener('keyup', function(event) {
  const searchText = event.target.value;
  // fetch search results from a server
  // and display them in the searchResults element
});

Output

When a user types in the search box, the keyup event is triggered and the search results are fetched from the server in real-time.

Explanation

The keyup event is triggered when a key on the keyboard is released after being pressed. The event object that is passed to the event listener function contains information about the key that was released, such as its keyCode and which modifier keys (Shift, Ctrl, Alt) were pressed at the same time.

In the example above, we attach an event listener to the search input element, and every time the user releases a key, the code inside the event listener function is executed. We extract the value of the input element and use it to fetch search results from a server using an API.

Use

The keyup event is useful for implementing real-time search features, form validation, and other interactive features that require immediate feedback to the user.

Important Points

• The keyup event is triggered whenever a key on the keyboard is released after being pressed.
• The event object passed to the event listener function contains information about the key that was released, such as its keyCode and which modifier keys (Shift, Ctrl, Alt) were pressed at the same time.
• The keyup event is widely used for implementing real-time search features, form validation, and other interactive features that require immediate feedback to the user.

Summary

The keyup event is a widely used keyboard event in JavaScript that is triggered each time a key on the keyboard is released after being pressed. This event is commonly used for implementing real-time search features, form validation, and other interactive features that require immediate feedback to the user. With the keyup event, developers can provide a seamless and responsive user experience for their users.