Rectangles¶

All the interesting stuff is in the JavaScript, so open up a JavaScript console and look at the console.log output. Here is the source code:

class Rect {
    // construct a rectangle from two diagonal corners, each
    // represented as a dictionary: {x, y}
    constructor(c1,c2) {
        // UL is upper left, LR is lower right
        this.ulx = Math.min(c1.x, c2.x);
        this.uly = Math.max(c1.y, c2.y);
        this.lrx = Math.max(c1.x, c2.x);
        this.lry = Math.min(c1.y, c2.y);
    }

    // the area method
    area () {
        const width = this.lrx - this.ulx;
        const height = this.uly - this.lry;
        return width*height;
    }
}

// some testing code
var origin = {x: 0, y: 0};
var p1 = {x: 10, y: 20};

var r1 = new Rect(origin, p1);
console.log(r1);
console.log("area is "+r1.area());