2024-05-06 20:40:05 +00:00
|
|
|
---
|
2024-10-30 17:04:36 +00:00
|
|
|
date: 20200930
|
2024-05-06 20:40:05 +00:00
|
|
|
id: e1048c95-3baa-445e-a943-bff7b86a0f29
|
|
|
|
|
title: Ambient Declarations
|
|
|
|
|
---
|
|
|
|
|
|
|
|
|
|
# Introduction
|
|
|
|
|
|
|
|
|
|
Ambient declarations allow you to safely use existing popular JavaScript
|
|
|
|
|
libraries and incrementally migrate your
|
|
|
|
|
JavaScript/CoffeeScript/Other-Compile-To-Js-Language project to
|
|
|
|
|
TypeScript.
|
|
|
|
|
|
|
|
|
|
# Declaration Files
|
|
|
|
|
|
|
|
|
|
Syntax is simple:
|
|
|
|
|
|
|
|
|
|
``` typescript
|
|
|
|
|
declare var foo: any
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
Declarations can be put in a `.ts` or `.d.ts` file, ie: `global.d.ts` or
|
|
|
|
|
`vendor.d.ts`
|
|
|
|
|
|
|
|
|
|
# Best Practices
|
|
|
|
|
|
|
|
|
|
- Use `.d.ts`
|
|
|
|
|
- Use [interfaces](20200929162220-interfaces) where possible
|
