JSONstringify

JSONstringify is a commonly used name for the JSON.stringify method in JavaScript. The standard API converts a JavaScript value into a JSON-formatted string, suitable for data storage or transmission. The function is part of the JSON object and is available in most JavaScript environments, including browsers and Node.js.

The basic signature is JSON.stringify(value, replacer, space). The value is the JavaScript value to serialize. The replacer can be a function or an array that controls how objects and their properties are stringified. The space parameter can be a number or a string and specifies indentation for pretty-printed output.

When serializing, only certain kinds of values are included. JSON.stringify uses the value’s toJSON method if present. It enumerates an object’s own enumerable properties; non-enumerable properties and properties with symbol keys are omitted. If a replacer function is provided, it is called for each property and its return value determines what is emitted; returning undefined omits the property. If replacer is an array, only keys present in the array are included. For top-level values, undefined, functions, and symbols produce undefined rather than a string.

Special numeric values such as NaN and Infinity become null. Undefined and functions are omitted when encountered as object properties, but in arrays they become null. Arrays preserve length, with holes filled as null in the output. Date objects serialize to an ISO date string via toJSON.

Circular references throw a TypeError. The resulting string can be parsed back with JSON.parse to recover the original data structure.