OnError Image

When images fail to load due to errors or slow network connections, developers can use the onerror event handler to display a fallback image or show an error message to users.

Syntax

<img src="image.jpg" onerror="this.onerror=null; this.src='backup_image.jpg';">

Or, as a separate function:

function imgError(image) {
    image.onerror = "";
    image.src = "backup_image.jpg";
    return true;
}

Example

<img src="image.jpg" onerror="this.onerror=null; this.src='backup_image.jpg';">

In this example, the onerror event is used to replace the original image source with a backup image if the primary image fails to load.

Explanation

The onerror event handler is triggered when an image fails to load. In the example, the this keyword refers to the image element that failed to load. The onerror attribute is set to a JavaScript expression that replaces the src attribute of the image with the URL of a backup image.

In the separate function example, the imgError function is called when the image fails to load, which sets the onerror event to an empty string to prevent the function from repeatedly executing and sets the src attribute to the URL of a backup image.

Conclusion

The onerror event handler provides a simple way to handle image loading errors and display fallback content. However, it is important for developers to optimize image sizes and network connections to prevent loading errors and improve user experience.