Stringify and Parse as Inverses

This is an example program that shows how to use the stringify() and parse() functions as inverses for JSON in JavaScript.

StringifyParseInverse.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="utf-8" />
		<meta name="viewport" content="width=device-width" />
		<title>XoaX.net's Javascript</title>
		<!-- Supply a transparent 1x1 favicon -->
		<link rel="icon" href="data:,">
		<script type="text/javascript" src="StringifyParseInverse.js"></script>
	</head>
	<body onload="Initialize()">
		<h1>Original Object</h1>
		<pre id="idObject1"></pre>
		<h1>Stringify Result</h1>
		<pre id="idObject2"></pre>
		<h1>Parsed Stringified Result</h1>
		<pre id="idObject3"></pre>
	</body>
</html>

StringifyParseInverse.js

function Initialize() {
	let qObject = {
		msName: "Jesus Christ",
		mqBirthday: new Date("0000-12-25"),
		mdAge: 30.5,
		mbIsGod: new Boolean(1),
		mbIsMan: true,
		mqBiologicalFather: null,
		msaApostles: ["Peter", "John", "James", "Thomas"],
		mfnMultiply: function(x) { return 100000*x;},
		mqParents: {sFather: "Joseph", sMother: "Mary"}
	};
	
	document.getElementById("idObject1").innerHTML = PrintAnObject("qObject", qObject);
	
	// This second parameter needs to convert functions to strings. Otherwise, functions will be skipped.
	// The third parameter '\t' is a spacing string or number. With tab, it just sets the indentation.
	let sJson = JSON.stringify(qObject, (key, value) => {
		if (typeof value === "function") {
			// Convert the function code to a string
			return value.toString();
		}
		return value;
	}, '\t');
	
	document.getElementById("idObject2").innerHTML = sJson;
	localStorage.setItem("StoredJSON", sJson);
	
	let sRetrieved = localStorage.getItem("StoredJSON");
	let qParsedObject = JSON.parse(sRetrieved, function (sKey, qValue) {
		// Functions and dates must be handled this way. Otherwise, they become strings.
		if (sKey === "mfnMultiply") {
			return eval("("+qValue+")");
		} else if (sKey === "mqBirthday") {
			return new Date(qValue);
		} else {
			return qValue;
		}
	});
	
	document.getElementById("idObject3").innerHTML = PrintAnObject("qParsedObject", qParsedObject);
}

function PrintAnObject(sName, qObject, sPre = "") {
  let sOutput = typeof(qObject) +  ": " + sName + " = " + qObject + '<br />';
  for (let sProperty in qObject) {
  	if (typeof(qObject[sProperty]) == "object") {
	    sOutput += PrintAnObject(sProperty, qObject[sProperty], sPre + "&nbsp;&nbsp;&nbsp;&nbsp;");
	  } else {
	  	sOutput += sPre+"&nbsp;&nbsp;&nbsp;&nbsp;"+typeof(qObject[sProperty])+': '+sProperty+' = '+qObject[sProperty]+'<br />';
	  }
  }
  return sPre + sOutput;
}