class Site {
    constructor(elements) {
        this.boards = [];
        this.elements = elements;
    }

    addBoard(noticeBoard) {
        this.boards.push(noticeBoard);
    }

    findBoardByName(Name) {
        this.boards.find(element => element===Name);
    }  
}

class Board extends Site {}
const mySite = new Board();

function 실험() {
    mySite.addBoard("첫번째")
    mySite.findBoardByName("첫번째")
}

console.log(실험())

이러면 콘솔창에 undefined 뜨던데 왜 인자 전달이 안되는거??