JAVASCRIPT

file_get_contents in javascript

$.post('phppage.php', { url: url }, function(data) {
    document.getElementById('somediv').innerHTML = data;        
});

file_get_contents in javascript

// You can use Fetch to get data.
fetch('http://example.com') // url here
  .then((response) => {
    return response.json(); // replace .json() to .text() for plain text
  })
  .then((daat) => {
    console.log(daat);
  });

file_get_contents in javascript

//Or You can use php.js library. Which allow some php functions for javascript. 
//file_get_contents() function one of them.

<script>
	var data = file_get_contents('Your URL');
</script>

//You can find more info about php.js : http://phpjs.org/