Arrays of Objects – JSON to Typedef Example
Convert JSON arrays containing objects into properly typed arrays with dedicated interfaces. See how element types are inferred from array contents.
What this demonstrates: This example shows arrays at multiple levels: an array of team members, an array of skills (strings), an array of projects, and an array of milestones within each project. The converter creates Member, Project, and Milestone types.
Paste JSON on the left to generate typedefs
Supports Nested Objects and Arrays
Our converter recursively processes deeply nested JSON structures, including arrays of objects, mixed-type arrays, and multi-level object hierarchies. Each nested object gets its own named interface (TypeScript) or class (C#) with properly typed properties.
Optional Fields and Mixed Types Handled
When a field is null in your JSON, it's automatically marked as optional in TypeScript (with ?) or nullable in C#. Arrays with mixed element types produce union types or fallback to object.
How to Use This JSON to Typedef Converter
Paste JSON
Paste or type your JSON into the input area on the left.
Choose Language
Select TypeScript or C# from the dropdown.
Copy Output
Your type definitions appear instantly. Click Copy to use them.