What can JavaScript Do?
Event handlers can be used to handle, and verify, user input, user actions, and browser actions:
- Things that should be done every time a page loads
- Things that should be done when the page is closed
- Action that should be performed when a user clicks a button
- Content that should be verified when a user inputs data
- And more ...
Many different methods can be used to let JavaScript work with events:
- HTML event attributes can execute JavaScript code directly
- HTML event attributes can call JavaScript functions
- You can assign your own event handler functions to HTML elements
- You can prevent events from being sent or being handled
- And more ...
More about events and event handlers in the HTML DOM chapters.