JSON Stringify

<!DOCTYPE html>
<html>
<body>

<h2>JSON.stringify() will remove any functions from an object.</h2>
<p>Convert functions into strings to keep them in the JSON object.</p>

<p id="demo"></p>

<script>
const obj = {name: "Ahmed", age: function () {return 30;}, city: "Cairo"};
obj.age = obj.age.toString();
const myJSON = JSON.stringify(obj);
document.getElementById("demo").innerHTML = myJSON;
</script>

</body>
</html>