Convert JS object to JSON string

Battle with browser compatibility

JSON.stringify() is a JavaScript staple since ECMAScript 5 (ES5). However, older browsers (looking at you IE6, IE7 👀) may not support it.

If your project needs to support these geriatric browsers, including a polyfill would help. You can easily download json2.js and add JSON.stringify() support to these older browsers.

Making the output pretty

JSON.stringify() has optional parameters that can help you impress anyone with your neat and pretty JSON strings:

const obj = { name: "John", age: 30 };
const beautifulJsonStr = JSON.stringify(obj, null, 4);
// Bumps up JSON's glamour quotient with 4-space indentation


The two optional parameters:

• Replacer can be a function or an array that controls how object values are stringified.
• Space is used for adding indentation to improve readability.

Dealing with problematic values

Objects, much like real-life, can sometimes be complicated (i.e., have cyclical references) or contain functions. JSON.stringify() does not handle them by default:

• Cyclical references: Need to be handled using a library or custom code. JSON is a "flat" format and can't handle the "roundabout" nature of your object.
• Functions: Are not a valid JSON data type. To include them, use a replacer that transforms function values into a string.

Important: Including function strings may result in a code that fails a JavaScript version of a TSA check (read: security risk).

Elevating security and selectivity

Just like in real life, not all object properties should travel:

• Exclude sensitive data: Use a custom replacer to leave out the non-essentials.
• Double-check for security: If you're using custom stringify methods, ensure they don't make you vulnerable to code contraband (malicious injections).

Cycling through stringification and parsing

Being fluent in both JSON.stringify() and JSON.parse() is a JavaScript badge of honor 🎖️. It allows you to turn your JavaScript object into a JSON string, send it around, and then welcome it back home as an object again.

Ensure you have checks in place to maintain the integrity and structure of your data while it's away on its journey.