Typescript learn

typescript.ts

//JS

typeof 42 //number
typeof 'str' //string
typeof true //boolean
typeof [] //object
typeof {} //object
typeof null //object
typeof undefined //undefined
typeof Symbol(); //symbol

//
let isComleted:boolean =false;

const decimal:number = 6; //number

const name1: string = 'Yauhen';

const sentence: string = `Hello ${name1}`


const u: undefined = undefined;

const n: null = null;
//function void with no return
const greetUserJs = (): void =>{
    alert('dasdasd');
}

//Array type

let list:number[] = [1,2,3]

let list2:Array<number> = [1,2,3]

//tuple
let x: [string,number]
x = ["hello",10]

//one line 

let y:[string,number] = ["good",42]


//ANY_TYPE
let y1:[any,any] = ["goodbuy",42]
let z1: Array<any> = [10,"dasdsa"]

//any type for string
let notSure: any=false;

//Enum
enum Directions{
    Up,
    Down,
    Left,
    Right
}

Directions.Up; //0
Directions.Down //1
//enum custom index
enum Directions2{
    Up=2,
    Down=4,
    Left,
    Right
}

Directions2.Up; //2
Directions2.Down //4