TypeScript tutorial: Declaration files

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[HendrikSwanepoelDucklake]

This is the best explanation that I could find on type definitions on the whole web! Thanks a lot!

[AustinBeaufort]

It's halfway through 2020, and this video is hands down the best I could find on .d.ts files, thank you!

[rammohanpolagani]

Nice explanation on declaration files and definatly types ones

[jamemamjame]

Wow end of series!!~
Thank you very much :)

[miskellil]

My respect from Algeria
Thanks a lots 👑👑

[brandonbahret]

So declaration files are synonymous with header files in C/C++


Makes sense.

[omgnowairly]

Few issues: you missed the optional parameter at the end of "random". The types in DefinatelyTyped are rarely accurate. You can't update them without dealing with sub project that manages the types and feeds into the main project. Often, the library authors are held hostage by the people running the type definitions. Save yourself dealing with 20 projects just to update types and use the inference in the editor or create your own definitions if you really need them.

[PhongNguyen-tplg]

Thanks & Great to have found you for better understanding Declaration in TS<3
Im newbie to TS too & still strugling how to use the .d.ts file.
Im really confused on some ponits:
1. When to use import/export & when to use ///<reference path= ... into a .d.ts file?
2. Do we have to use Export keyword for every .d.ts file we create.?
3. Below in a project, i found a file named 'global.d.ts' without 'export' keyword. but as i read & watch some docs & vids, they all have 'export' keyword. How does other files know to implement this 'global.d.ts'? ^^
---- global.d.ts
declare namespace Process {
interface ProcessEnv {
PROXY_MODE: string;
NEXT_PUBLIC_STATIC_PATH: string;
NEXT_PUBLIC_API_URL: string;
NEXT_PUBLIC_API_KEY: string;
}
}

declare namespace jest {
interface Options {
media?: string;
modifier?: string;
supports?: string;
}

interface Matchers<R> {
toHaveStyleRule(property: string, value?: Value, options?: Options): R;
}
}

[H-vi]

When you stop to read about lodash and strange export functionality.

[denysabramov]

Русский штоле? Сразу слышно. Ухо режет акцент.

[humanthree]

How can I know which version of types package corresponds to which version of the actual package?