how to check if url is valid code example

Example 1: how to check if a url is up php

<?php
$url = 'http://google.com';

if(@file_get_contents($url)){
	
	echo "Website is up";
	
} else {
	
	echo "Website is down";
	
}

?>

Example 2: javascript determine if string is valid url

function isValidHttpUrl(string) {
  let url;
  
  try {
    url = new URL(string);
  } catch (_) {
    return false;  
  }

  return url.protocol === "http:" || url.protocol === "https:";
}