دليل مساعد TypeScript: تعلّم المفاهيم الأساسية وال أفضل الممارسات

let a: number = 10;
let s: string = "TypeScript";
let b: boolean = true;
let arr: number[] = [1, 2, 3];
let tuple: [string, number] = ["TS", 2025];
let anyValue: any = "المرونة";
let unknownVal: unknown = 5;
let notDefined: undefined = undefined;
let notPresent: null = null;

let id: number | string = 42;
let direction: 'left' | 'right' = 'left';

type Point = { x: number; y: number };
interface Person { name: string; age: number; }
let user: Person = { name: "Alice", age: 25 };

function sum(a: number, b: number): number {
  return a + b;
}
const multiply = (a: number, b: number): number => a * b;
function log(msg: string): void { console.log(msg); }

class Animal {
  name: string;
  constructor(name: string) { this.name = name; }
  move(distance: number = 0): void { console.log(`${this.name} moved ${distance}`); }
}

class Point {
  constructor(private x: number, private y: number) {}
}

function identity(arg: T): T { return arg; }
let output = identity("myString");

enum ResourceType { BOOK, FILE, FILM }
let r: ResourceType = ResourceType.BOOK;

let someVal: unknown = "Hello";
let strLength: number = (someVal as string).length;

// تصدير
export function foo() {}
// استيراد
import { foo } from "./module";

Partial, Required, Readonly, Pick, Omit, Record

function padLeft(value: string, padding: string | number) {
  if (typeof padding === "number") {
    return Array(padding + 1).join(" ") + value;
  }
  return padding + value;
}