title: Why a value incremented in x while not in found object?
body: <p><strong>Code</strong>:</p>
  
  <pre><code>const x = [{a: 1}, {b: 2}];
  let found = x.find(el =&gt; el.a === 1);
  if(found) found = {...found, a: found.a++};
  console.log(x); // [{a: 2}, {b: 2}];
  console.log(found) // {a: 1}
  </code></pre>
  
  <p>Why this code changed the value of <strong>a</strong> in <strong>x</strong> while not in <strong>found object</strong>??</p>