Check if image exists on server using JavaScript?

Question

Using javascript is there a way to tell if a resource is available on the server? For instance I have images 1.jpg - 5.jpg loaded into the html page. I\'d like to call a Jav

Answer 1

Basicaly a promisified version of @espascarello and @adeneo answers, with a fallback parameter:

const getImageOrFallback = (path, fallback) => {
  return new Promise(resolve => {
    const img = new Image();
    img.src = path;
    img.onload = () => resolve(path);
    img.onerror = () => resolve(fallback);
  });
};

// Usage:

const link = getImageOrFallback(
  'https://www.fillmurray.com/640/360',
  'https://via.placeholder.com/150'
  ).then(result => console.log(result) || result)

// It can be also implemented using the async / await API.

Note: I may personally like the fetch solution more, but it has a drawback – if your server is configured in a specific way, it can return 200 / 304, even if your file doesn't exist. This, on the other hand, will do the job.