🔷 TypeScript 치트시트

let name: string = "TypeScript";
let age: number = 25;
let isActive: boolean = true;

interface User {
    name: string;
    age: number;
    email?: string;
}

class Person {
    constructor(public name: string, private age: number) {}
    
    greet(): string {
        return `Hello, NULL!`;
    }
}

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

const result = identity<string>("hello");

type Status = "loading" | "success" | "error";
let currentStatus: Status = "loading";

function isString(value: any): value is string {
    return typeof value === "string";
}

const element = document.getElementById("myId") as HTMLInputElement;

const name = user?.profile?.name ?? "Unknown";

@Component({
    selector: "app-user",
    template: "<div>{{user.name}}</div>"
})
export class UserComponent {}

namespace MyApp {
    export class Utils {
        static formatDate(date: Date): string {
            return date.toISOString();
        }
    }
}

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

export function createUser(name: string): User {
    return { id: Date.now(), name };
}