title: php json decode special characters
body: <p>I wan't decode json string from file, but there is problem with special characters(for ex. '™', '★'..). My code from PHP</p>
  
  <pre><code>$price_string = file_get_contents("/var/www/bot/price.json");
  $price = json_decode($price_string, true);
  echo $price["StatTrak™ P250 | Mehndi (Field-Tested)"];
  </code></pre>
  
  <p>Result should be 12.01, but the result is this:</p>
  
  <pre><code>Notice: Undefined index: StatTrak� P250 | Mehndi (Minimal Wear) in /var/www/html/menu.php on line ..
  </code></pre>
  
  <p>And the JSON string is for example:</p>
  
  <pre><code>{
      "★ Huntsman Knife | Boreal Forest (Well-Worn)": 62.84,
      "StatTrak™ P250 | Mehndi (Field-Tested)": 12.01
  }
  </code></pre>