class Ball {
    constructor() {
        this.x = 90;
        this.y = 80;
    }
    move(dir) {
        if (dir === 'left') {
            this.x - 1;
        } else if (dir === 'right') {
            this.x- 1;
        }
    }
}
let ball = new Ball;
document.addEventListener('keydown', (e) => {
    if (e.keyCode === 
'left key code') {
    ball.move('left')
} else if (e.keyCode === 'right key code') {
    ball.move('right')
}
})