title: Wrong format in JSON String
body: <p>I have this piece of code </p>
  
  <pre><code>$bom = Foo::getFooFromName($fooName);
              $content = json_decode($foo['content'], true);
              $content[] =  $foo_name . ':'.  $qty  ;
  
              Foo::where('id', $foo['id'])-&gt;update([
                  'content' =&gt; json_encode($content, JSON_FORCE_OBJECT | JSON_UNESCAPED_SLASHES)
              ]);
  </code></pre>
  
  <p>that when executed it fives me this JSON STRING:</p>
  
  <pre><code>{"0":{"171":"3"},"1":"396:3"}
  </code></pre>
  
  <p>This part already exists, so the JSON string is correct: {"0":{"171":"3"} but when I run `$content[] =  $foo_name . ':'.  $qty  ;</p>
  
  <pre><code>            Foo::where('id', $foo['id'])-&gt;update([
                  'content' =&gt; json_encode($content, JSON_FORCE_OBJECT | JSON_UNESCAPED_SLASHES)
              ]);
  </code></pre>
  
  <p>It seems that I am unable to properly format the JSON String to look like this:</p>
  
  <pre><code>{"0":{"171":"3"},"1":{"396":"3"}}
  </code></pre>
  
  <p>Any idea would be greatly appreciated.</p>