title: Get json object's value in php if its name contains dots in PHP
body: <p>I have a json like the following</p>
  
  <pre><code>{"root":{
                  "version":"1",
                  "lastAlarmID":"123",
                  "proUser":"1",
                  "password":"asd123##",
                  "syncDate":"22-12-2014",
                  "hello.world":"something"
  }
  }
  </code></pre>
  
  <p>After <code>json_decode()</code>, I can get all the values except that of the last one <code>hello.world</code>, since it contain a dot.</p>
  
  <p><code>$obj-&gt;root-&gt;hello.world</code> doesn't work. I got solutions for doing it in Javascript but I want a solution in php.</p>