class Circle {
    // 构造器。
    constructor(x, y, d, c) {
        this.x = x;
        this.y = y;
        this.d = d;
        this.c = c;
    }
    // draw中文：画。
    draw() {
        noStroke();
        fill(this.c);
        ellipse(this.x, this.y, this.d);
    }
}

// 全局常量或变量。
const width = 300;
const height = 500;
let c1, c2;

function setup() {
    createCanvas(width, height);
    c1 = new Circle(90, 90, 80, "#DDDD00");
    c2 = new Circle(90, 180, 80, 'red');
}

function draw() {
    background(150);
    c1.draw();
    c2.draw();
}