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ROMITJSON LEARNING GUIDES

Learn JSON

Learn how JSON represents data, how to read objects and arrays, and how to catch mistakes before they break an API request or configuration file. Start with the syntax reference below, then follow a focused guide for the task you are working on.

Showing 6 tutorials

Basics

JSON Basics: Syntax, Types, Objects, and Arrays

Learn how JSON objects group named properties and how arrays keep values in order. This guide explains all six JSON value types, nesting, key and string quoting, commas, colons, and paired brackets. Follow examples such as user.profile.city to see how to reach a nested value, then check a document for valid syntax.

Beginner8 min readStart here Formatting

How to Format JSON for Readability

Compare a compact JSON document with an indented version and see why both can represent the same value. The guide covers common indentation choices, when readable formatting helps with reviews or debugging, and when minifying is useful for compact output. It also explains the limits: formatting changes whitespace, but it cannot repair invalid JSON or compress the data.

Beginner5 min read Validation

How to Find and Fix JSON Syntax Errors

See how missing commas, misplaced colons, single quotes, unquoted keys, trailing commas, comments, and mismatched brackets make JSON invalid. Each issue is paired with the rule to check, followed by a debugging workflow for using parser locations without assuming they point to the original mistake. The guide also separates valid syntax from application-specific data requirements.

Beginner9 min read Schema

JSON Schema: Define and Validate Data

Learn how a JSON Schema describes the expected shape of a separate JSON document. The guide explains types, properties, required, array items, nested objects, and additional properties using a Draft 2020-12 example. It also shows why a syntactically valid document can still fail schema validation, and why schemas inferred from sample data need review.

Beginner10 min read APIs

Working with JSON in APIs

Learn where JSON fits into HTTP requests and responses, including request bodies, content type, status codes, and API-specific response structures. The guide compares possible success and error payloads, explains nested fields and pagination metadata, and offers a workflow for inspecting a response. It distinguishes JSON syntax checks from checking data against an API contract.

Beginner8 min read Conversions

JSON Conversion Guide: CSV, YAML, XML, and TypeScript

Compare JSON with CSV, YAML, XML, and TypeScript, then choose an output based on what the receiving tool expects. The guide explains why CSV suits consistently shaped rows, why nested objects need conversion rules, and why generated TypeScript is only an inferred starting type. A practical workflow covers preserving the source, checking output, and testing nulls, arrays, and nested values.

Beginner9 min read

JSON syntax at a glance

JSON (JavaScript Object Notation) is a text format for representing structured data. An object groups named values inside braces; an array holds an ordered list inside brackets. Both can contain other objects and arrays, which is why an API response can have several levels of nested data.

A small JSON example

{
  "name": "Ada",
  "active": true,
  "roles": ["editor", "reviewer"],
  "profile": { "location": null }
}

Here, name is a string, active is a boolean, roles is an array, and profile is a nested object.

Rules that prevent common errors

  • Put double quotes around every key and every string value.
  • Separate object properties and array items with commas; do not add a comma after the last item.
  • Use JSON values: objects, arrays, strings, numbers, true, false, and null.
  • JSON has no comments, undefined, or trailing commas.

null, an empty value such as "", and a missing property mean different things. Keep that distinction when reading or validating data.

A practical workflow for working with JSON

  1. Read the structure. Find the outer object or array first, then follow the keys and indexes to the value you need. The JSON basics guide walks through these parts.
  2. Make it readable. Indentation changes how JSON is displayed, not its data. Use the JSON Formatter to expand compact JSON, or the JSON Viewer to explore nested values.
  3. Check syntax before debugging the data. A missing comma or quote makes the whole document invalid. The JSON Validator helps identify syntax errors; a valid document can still have the wrong values or shape for an application.
  4. Check the expected shape when needed. If an API or application requires specific fields and types, describe those requirements with a JSON Schema and validate the data against it.

For hands-on practice, browse the fictional JSON datasets. They include nested records, API response examples, empty arrays, and explicit null values, so you can see how those cases appear in actual JSON.

Learn by working with examples

Browse fictional JSON datasets to practice with realistic object shapes and edge cases, or explore the complete set of RomitJSON tools. The examples in these guides are illustrative; review them before using them in an application.