Typescript. d.ts files
needed to use js code in ts code through declarations
looks like this stackoverflow post describes it the best
as i understood js files and
Typescript. Modules
Пантелеев СтаниславModules also created to group out code. Lets look at example
hi.ts // this will be the module
export default function sayHi() { console.log(‘hi, there’);
Typescript. Namespaces
Пантелеев Станиславnamespaces allow logically group our code
namespace Animals { interface Animal { sayHi(): void } class Dog implements Animal { sayHi(): void { console.log(‘av-av’); }
Typescript. Generics
Пантелеев Станиславfunction foo<T>(x: T): T { // calc return x; } console.log(foo<string>(‘hi, there’)); console.log(foo<number>(123)); // — extends for generics function foo2<T extends { name: string
Typescript. Type Assertions
Пантелеев Станиславas it was mentioned in DataTypes post there are 2 ways of assertions through as and <type> operators
// Type assertions const myCanvas =
Typescript. Static methods and fields
Пантелеев СтаниславHere is the same idea as in C#, Java and other langs. Static methods are methods that more devoted to class rather than to instance
Typescript. get / set modifiers
Пантелеев Станиславworks only with ecmaScript2015
class Man { private _name: string = «DefaultName»; get name(): string { return this._name } set name(value: string) { console.log(‘been here’);
Typescript. Access Modifiers
Пантелеев Станиславpublic // by default
private // only inside class
protected // only inside class and its inheritors
readonly // readonly
a little bit of
Typescript. Abstract classes and Interfaces
Пантелеев СтаниславABSTRACT CLASSES EXAMPLE abstract class Prayer { abstract pray: string; abstract makeSins(): void; doPray(): string { return this.pray; } } class Muslim extends Prayer {
TypeScript. Class Inheritance
Пантелеев Станиславenum Sex { Man, Woman } class Man { name: string = «DefaultName»; family: string = «DefaultFamily»; age: number = 18; readonly sex: Sex.Man constructor(name: