Use unknown Instead of any for Values with an Unknown Type

Overview

unknown is the type-safe cousin of any.

When you don't know a value's type, use unknown. It forces you to narrow the type before using it, preventing bugs that any would allow.

When to Use This Skill

• Parsing JSON or YAML
• Receiving data from external sources
• Working with user input
• Writing functions that accept anything
• Replacing any with something safer

The Iron Rule