змінна

A named storage location that holds a value which can change during program execution

let count: number = 5;

тип

A classification of data that specifies what kind of value a variable can hold (e.g., number, string, boolean)

const name: string = 'Alice';

функція

A reusable block of code that performs a specific task and can accept parameters and return a value

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

клас

A blueprint for creating objects that defines properties and methods shared by instances

class Car { brand: string; }

масив

An ordered collection of elements of the same type, accessed by index

const numbers: number[] = [1, 2, 3];

об'єкт

A collection of key-value pairs representing properties and their values

const person = { name: 'John', age: 30 };

інтерфейс

A contract that defines the structure and types of properties and methods an object must have

interface User { id: number; name: string; }

загальний тип

A type parameter that allows a function or class to work with multiple types while maintaining type safety

function identity<T>(arg: T): T { return arg; }

декоратор

A special declaration that attaches metadata to a class, method, or property and modifies its behavior

@Component() class MyComponent {}

модуль

A file or collection of code that encapsulates related functionality and can be imported/exported

export const greet = () => 'Hello';

набір

A union type that allows a variable to have one of several specified types

type Status = 'success' | 'error' | 'pending';

перевизначення методу

The process of providing a new implementation of a method in a subclass that already exists in the parent class

class Dog extends Animal { bark() { ... } }

асинхронна функція

A function that returns a Promise and can pause execution using the await keyword

async function fetchData() { const data = await fetch(url); }

зберігання типу

TypeScript's ability to preserve type information at runtime through metadata reflection

Reflect.getMetadata('design:type', target, propertyKey)

умовний тип

A type that selects one of two types based on a condition, enabling dynamic type selection

type IsString<T> = T extends string ? true : false;