html image doesn't show code example

Example 1: css hide image if not found

<!-- hide image if not find -->
<img src="image.png" onerror="this.style.display='none'"/>

<!-- show image after load -->
<img src="image.png" style="display: none" onload="this.style.display=''">

Example 2: image doesn't show in html

<img src="dog.jpg">
<img src="la.jpg">