nalendro nalendro16

## optional type
interfaces ItemProps {
  name: string,
  id: number
  active?: boolean
}
data?: Array<String>

## medium-typescript.ts
let character: string
let age: number
let isLoggedin: boolean

character = 'agung'
age = 23
isLoggedin = true
	interfaces ItemProps {
	name: string,
	id: number
	active?: boolean
	}
	data?: Array<String>
	let character: string
	let age: number
	let isLoggedin: boolean

	character = 'agung'
	age = 23
	isLoggedin = true