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Learning TypeScript 2.x - Second Edition
book

Learning TypeScript 2.x - Second Edition

by Remo H. Jansen
April 2018
Beginner content levelBeginner
536 pages
13h 21m
English
Packt Publishing
Content preview from Learning TypeScript 2.x - Second Edition

The ECMAScript specification type definitions (lib.d.ts)

The TypeScript compiler automatically includes type definitions for the ECMAScript version that we are targeting. For example, if we target ES5, we will not be able to access the Promise API, because it is part of the ES6 specification:

const p = Promise.resolve(1); // Error 

However, TypeScript allows us to import the type definitions for a proposal instead of an entire ECMAScript specification. For example, we can target ES5 and use the Promise API by adding the following to our tsconfig.json file:

"lib": ["es5", "dom", "es2015.promise"] 

The preceding setting is indicating to the TypeScript compiler that we want it to import the type definitions for the entire ECMAScript 5 specification, ...

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Publisher Resources

ISBN: 9781788391474Supplemental Content