What is JSON Parse? JSON Parse Definition & Examples

JSON wasn’t invented until 2001, but it pretty rapidly became the recognized standard for handling data between a web server and client. Whether you’re building your own API or working with n existing web service, there’s a strong chance that you’ll find yourself working with JSON.

And if you’re using JSON to work with data from a server, the parse method is going to become a familiar sight. Fortunately, it will appear very familiar to anyone who has a passing familiarity with JavaScript. Whether you’re trying to make sense of an API’s syntax or determine if a JSON-RPC is an appropriate format for your new web service, there are a few things you should know.

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What is JSON Parse?

Understanding the JSON parse function first requires a basic understanding of what JSON is. Short for JavaScript Object Notation, it uses the syntax of JavaScript to transform data written into JavaScript into a simple string. Generally, JSON is used to replicate JavaScript objects — which are represented by a series of key-value pairs — but JSON can also be used to create arrays.

JSON objects are stored as simple strings but are written in a way that resembles common JavaScript structures. That’s where the JSON parse method comes in. The parse method at its most basic converts a JSON string into a JavaScript object or an array, but there’s room to transform that data at the same time. Parse is commonly used in conjunction with APIs, since it allows a server to efficiently store data that can then be easily converted into the user interface by converting it back to JavaScript.

How Does JSON Parse Work?

The JSON parse function takes data that’s in a text format and then converts it into JavaScript. Usually, these take the form of JavaScript objects, but the parse function can be used directly on arrays as well. Since both objects and arrays are presented as key-value pairs, JSON is a data management platform that can be interpreted and written easily by someone with a passing knowledge of JavaScript.

The method itself is similarly simplistic. The parse method accepts one mandatory parameter: the string to be parsed. It also allows for an optional reviver parameter that can modify the value being parsed. A reviver is often expressed as a function and can be used for everything from running calculations to filtering results to formatting names.

Who is JSON Parse For?

The JSON parse function is the sort of specialized JavaScript method that you’ll see all the time if you work with web server APIs and rarely if never otherwise. While there are other data storage types available, the ease with which JSON can be converted into text (using the companion JSON stringify function) and then directly back into JavaScript makes it a clean way to take server-side data and present it in a stylish and user-friendly format.

Why is JSON Parse Important?

The JSON parse method is important because of how easy it makes data management between a server and a client. Since JSON objects can be saved as simple text files, reading the data is easy for people with even a passing understanding of JS. And since JavaScript is something of a lingua franca in the coding community, it makes manipulating that data a breeze too.

Any number of methods or expressions you’d use in JavaScript can be transplanted as the reviver parameter. Even if the arguments in favor of JSON don’t convince you, it continues to be the primary data exchange format in REST APIs, and the RESTful methodology will continue to be a prevalent architecture for the foreseeable future.

What Can You Expect From JSON Parse?

JSON parse is an exceedingly utilitarian method, so you can generally expect straightforward results. As long as you’re clean with your object naming conventions, a parse with a single parameter should be smooth. The fact that JSON objects are almost identical to JavaScript objects means that syntax issues are generally easy to resolve as well. SyntaxErrors will alert you of issues with improperly formatted JSON, and they’re the most typical issue you’ll face. With the exception of the date/time format, JSON supports all data types that JavaScript does as well.

Use Cases and Examples of JSON Parse

The JSON parse function is straightforward, but there is some flexibility in its use cases. It will primarily be utilized as a means to transfer raw text into actionable data that you can manipulate, but revivers allow for additional transformations on the way to the user. Here are some examples of how JavaScript’s JSON.parse function can be used with an example JSON object.

The following stores a JSON object as a variable named object.

var object = '{"first_name":"Ben", "last_name":"Doe", "age":30, "city":"Philadelphia", "alive": "true"}'

The following converts that object as JavaScript that is then stored as the variable result.

var result = JSON.parse(object);

With those key-value pairs assigned, specific characteristics can be presented with dot notation and manipulated like any JS object. The following will print a formatted version of the name “Ben Doe”.

console.log(object.first_name + " " + object.last_name);

A reviver can also be used to manipulate the information without having to first save it as an object, as in the example below which can verify a user’s age within the parse method.

JSON.parse(object, function() {
if (this.age >= 21) {return true}
else {return false}};

What Are The Benefits of JSON Parse?

JSON is inherently designed to make managing data as easily as possible, and that philosophy expresses itself very well through the parse function. A single line of code allows you to transform a string into actionable data, and the revivers that can modify them follow traditional JS syntax. And the support for all data types means that you can worry less about edge cases that might require you to change up your code.

Using JSON with the parse method is a more practical choice in terms of performance as well. JSON files can be parsed much faster than some of the other data storage alternatives, and they’re significantly more compact in size as well. The human-readable format of JSON files also ensures a transparent and straightforward choice.

How Does JSON Parse Compare to Competitors?

The main competitor to JSON is XML, and the differences between the two are stark. While the JSON parse method can convert text to JavaScript in a single line with a single variable, the same process can take dozens or hundreds of lines with XML. It’s a more verbose language, and that makes it both slower to load and larger in size. It’s a less nimble choice, especially when you’re dealing with browser-based or mobile native clients.

That said, the lightweight and nimble design of JSON can also sometimes be a liability. Unlike XML, JSON doesn’t support inline comments, and it doesn’t support schema. When dealing with more complex data or with data in enormous quantities, XML can be a more efficient format.

Summary

If you need to transfer data from a server to a browser or mobile app, you’re going to see a lot of the JSON parse function. Over the course of a decade and a half, it’s become the standard for handling data, and there are few signs of that changing anytime soon. While XML still may be the preferred choice in legacy systems or edge cases, JSON is too nimble and too easy-to-read a format. And fortunately, the simplicity and familiarity of JSON parse make it an easy new tool to add to your kit.

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