TypeScript

Переменные

let a: number = 1;
a = "hello"; // Type 'string' is not assignable to type 'number'

Функции

function add(a: number, b: number): number {
  return a + b;
}

Классы

class Person {
  name: string;
  constructor(name: string) {
    this.name = name;
  }
}

let person = new Person("allen");

Перечисления

enum Color {
  Red,
  Green,
  Blue,
}

let color: Color = Color.Red;

Массивы

let array: number[] = [1, 2, 3];

Type

type Person = {
  name: string;
  age: number;
};

let person: Person = {
  name: "allen",
  age: 30,
};

Типы данных

Тип	Описание
number	Число
string	Строка
boolean	Логический тип
any	Любой тип
void	Ничего

Union

function showId(id: number | string) {
  console.log(id);
}

showId(1);
showId("1");

Optional

Function

function greet(firstName: string, lastName: string, patronymic?: string) {
  console.log(`Hello, ${firstName} ${lastName} ${patronymic}`);
}

Class

class Person {
  firstName: string;
  lastName: string;
  patronymic?: string;

  constructor(firstName: string, lastName: string, patronymic?: string) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.patronymic = patronymic;
  }
}

Type

type Person = {
  firstName: string;
  lastName: string;
  patronymic?: string;
};

Абстрактные классы

abstract class PLayer {
  hp: number;
  speed: number;
  constructor(hp: number, speed: number) {
    this.hp = hp;
    this.speed = speed;
  }
}

class CT extends PLayer {
  constructor(hp: number, speed: number) {
    super(hp, speed);
  }

  defuse(): void {
    console.log("defuse");
  }
}

class T extends PLayer {
  constructor(hp: number, speed: number) {
    super(hp, speed);
  }

  plant(): void {
    console.log("plant");
  }
}

Getter and Setter

class Student {
  fullName: string;
  private _mark: number;
  constructor(fullName: string, mark: number) {
    this.fullName = fullName;
    if (mark > 0 && mark <= 10) {
      this._mark = mark;
    } else {
      throw new Error("Mark must be between 0 and 10");
    }
  }

  get mark() {
    return this._mark;
  }

  set mark(mark: number) {
    if (mark > 0 && mark <= 10) {
      this._mark = mark;
    } else {
      throw new Error("Mark must be between 0 and 10");
    }
  }
}

const student = new Student("Allen", 10);
console.log(student.mark);
student.mark = 15;
console.log(student.mark);

Generics

function createPair<T, U>(a: T, b: T, c: U, d: U) {
  return [
    [a, b],
    [c, d],
  ];
}

class Student {
  fullName: string;
  marks: number[];
  constructor(fullName: string, marks: number[]) {
    this.fullName = fullName;
    this.marks = marks;
  }
}

class Teacher {
  fullName: string;
  subject: string;
  constructor(fullName: string, subject: string) {
    this.fullName = fullName;
    this.subject = subject;
  }
}

const student1 = new Student("John Doe", [90, 95, 80]);
const student2 = new Student("Jane Doe", [85, 90, 95]);

const teacher1 = new Teacher("John Smith", "Math");
const teacher2 = new Teacher("Jane Smith", "English");

const pair = createPair(student1, student1, teacher1, teacher1);

console.log(pair);

Interfaces

Статические поля и методы