title: What is the problem with this JSON string?
body: <p>This is from data submitted with a form. I have no control over the generation of the JSON because it is done using <code>JSON.stringify()</code>. On the server I receive the following JSON string which I want to parse back into a Javascript object using <code>JSON.parse()</code>.</p>
  
  <p>However there seems to be a problem at the <code>"uploadedFilename"</code> part which <code>JSON.parse()</code> can't handle but I don't understand why or what it is:</p>
  
  <pre><code>[
  '{"originalFilename":"A.jpg","uploadedFilename":"A-15904372.jpg","size":9149216,"type":"image/jpeg","isUploading":false,"isUploaded":true,"uploadPromise":{},"uploadProgress":100,"invalidFileMessage":null}'
  ,
  '{"originalFilename":"B.jpg","uploadedFilename":"B-972341252.jpg","size":9149216,"type":"image/jpeg","isUploading":false,"isUploaded":true,"uploadPromise":{},"uploadProgress":100,"invalidFileMessage":null}'
  ]
  </code></pre>
  
  <p><code>JSON.parse()</code> return the following error:</p>
  
  <blockquote>
    <p>SyntaxError: Unexpected token u in JSON at position 0</p>
  </blockquote>
  
  <p>So I put the code into <a href="https://jsonformatter.org/json-parser" rel="nofollow noreferrer">https://jsonformatter.org</a> and the error says:</p>
  
  <blockquote>
    <p>Parse error on line 1:<br>
    [    '{"originalFilename"</p>
    
    <p>-------^ Expecting 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '[', ']', got 'undefined'</p>
  </blockquote>