Untitled

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>

<script id="jsbin-javascript">
//Here you get an error when trying to change AGE because AGE is a constant value and can not be changed once set.

/*
* const AGE = 27;
* AGE = 29;
* console.log(AGE);
*/


// Here we can change the value of age because an object is a reference type, the pointer didn't change, only the value.
const OBJ = {
  age: 27
};

console.log(OBJ);
OBJ.age = 30;
console.log(OBJ);
</script>


<script id="jsbin-source-javascript" type="text/javascript">//Here you get an error when trying to change AGE because AGE is a constant value and can not be changed once set.

/*
* const AGE = 27;
* AGE = 29;
* console.log(AGE);
*/


// Here we can change the value of age because an object is a reference type, the pointer didn't change, only the value.
const OBJ = {
  age: 27
};

console.log(OBJ);
OBJ.age = 30;
console.log(OBJ);</script></body>
</html>