Type Assertions

Type Assertions

• Less Specific 타입에서 More Specific 타입으로
• 변수 as MoreSpecificType
• (변수 as MoreSpecificType).method

// HTMLElement(less specific) => HTMLCanvasElement
const myElement:HTMLElement =  document.getElementById("main_canvas")
const myCanvas:HTMLCanvasElement = document.getElementById("main_canvas") as HTMLCanvasElement;

Definitive Assignment Assertion

• key!:string