Upload file with AJAX jquery - php

Question

I'm trying to upload a single file with JQUERY AJAX. I found this old thread - Jquery ajax single file upload
I followed the codes, but I kept getting the "Not Set" error on my php script.
Here's my HTML
<form id="fileinfo" enctype="multipart/form-data" method="post" name="fileinfo">
<label>File:</label>
<input type="file" name="file" required />
</form>
<input type="button" id="upload" value="Upload"></input>
<div id="output"></div>
Here's my Jquery code. I
used latest uncompressed CDN - https://code.jquery.com/jquery-3.3.1.js
$( document ).ready(function() {
$('#upload').on('click', function(){
var formData = new FormData();
formData.append('file', $('input[type=file]')[0].files[0]);
$.ajax({
url: 'upload.php',
type: 'POST',
data: formData,
success:function(data){
$('#output').html(data);
},
cache: false,
contentType: false,
processData: false
});
});
});
Here's my php script (upload.php)
<?php
if(isset($_GET['file'])){
$filename = $_FILES['file']['name'];
if(isset($filename) && !empty($filename)){
echo 'File available';
}else{
echo 'please choose a file';
}
} else{
echo 'No file';
}
?>
Update: Changed my PHP code with below and it fixed the issue.
<?php
$info = pathinfo($_FILES['file']['name']);
$ext = $info['extension']; // get the extension of the file
$newname = "newname.".$ext;
$target = 'files/'.$newname;
move_uploaded_file( $_FILES['file']['tmp_name'], $target);
if (file_exists("files/{$newname}")) {
echo "Uploaded!";
}
?>