JSON Serialization, Validation & Tree Inspection: Complete Guide

JavaScript Object Notation (JSON) is the universal data interchange format for RESTful APIs, cloud microservices, and web configuration files. Mastering proper JSON syntax, serialization patterns, and debugging techniques is an indispensable developer skill.

Core JSON Data Types & Syntax Rules

JSON is built on two primary structures: collections of name/value pairs (objects) and ordered lists of values (arrays). Supported primitive types include:

• String: Double-quoted Unicode text (e.g., "name": "ToolkitBank"). Single quotes are invalid in strict JSON.
• Number: Integer or floating-point numbers without quotes (e.g., "price": 49.99).
• Boolean: true or false.
• Array: An ordered collection inside square brackets [1, 2, 3].
• Object: A collection inside curly braces {"key": "value"}.
• Null: A blank value represented as null.

Common JSON Formatting Mistakes

1. Trailing Commas: Placing a comma after the final item in an object or array (e.g., {"a": 1, "b": 2,}) causes fatal parse errors in strict JSON parsers.
2. Single Quotes Instead of Double Quotes: JSON specification RFC 8259 strictly requires double quotation marks around both keys and string values.
3. Unescaped Control Characters: Newlines inside strings must be escaped as \n rather than literal line breaks.