HTML events are "things" that happen to HTML elements.
When JavaScript is used in HTML pages, JavaScript can "react" on these events.
An HTML event can be something the browser does, or something a user does.
Here are some examples of HTML events:
Often, when events happen, you may want to do something.
JavaScript lets you execute code when events are detected.
HTML allows event handler attributes, with JavaScript code, to be added to HTML elements.
With single quotes:
With double quotes:
In the following example, an onclick attribute (with code), is added to a button element:
See this example:
In the example above, the JavaScript code changes the content of the element with id="demo".
In the next example, the code changes the content of its own element (using this.innerHTML):
See this example:
JavaScript code is often several lines long. It is more common to see event attributes calling functions:
See this example:
Here is a list of some common HTML events:
| Event | Description |
|---|---|
| onchange | An HTML element has been changed |
| onclick | The user clicks an HTML element |
| onmouseover | The user moves the mouse over an HTML element |
| onmouseout | The user moves the mouse away from an HTML element |
| onkeydown | The user pushes a keyboard key |
| onload | The browser has finished loading the page |
Event handlers can be used to handle, and verify, user input, user actions, and browser actions:
Many different methods can be used to let JavaScript work with events:
