onhashchange

The onhashchange event is a JavaScript event that is triggered when the fragment identifier of the URL changes. This can occur when the user navigates through the browser's history or when the hash value is modified programmatically. The event is particularly useful for single-page applications (SPAs) where different views or states are managed through URL fragments.

The onhashchange event is supported in all modern web browsers, including Chrome, Firefox, Safari, and Edge. It is not supported in Internet Explorer versions below 8. The event handler can be attached to the window object using the addEventListener method or by assigning a function to the window.onhashchange property.

When the onhashchange event is triggered, an event object is passed to the event handler function. This object contains information about the event, including the old and new URL values. The oldURL property holds the URL before the hash change, and the newURL property holds the URL after the hash change.

Here is an example of how to use the onhashchange event:

window.addEventListener('hashchange', function(event) {

console.log('Old URL: ' + event.oldURL);

console.log('New URL: ' + event.newURL);

});

In this example, an event listener is added to the window object for the hashchange event. When the hash changes, the event handler function is called, and it logs the old and new URL values to the console.

The onhashchange event is a powerful tool for managing navigation and state changes in web applications, providing a way to respond to changes in the URL fragment without requiring a full page reload.