ES6 Constructor Pattern

constructor.js

class Car {
    constructor(opts) {
        this.model = opts.model;
        this.year = opts.year;
        this.miles = opts.miles;
    }
    toString() {
        return this.model + ' has driven ' + this.miles + ' miles';
    }
}

// Usage
var civic = new Car({
    model: 'Honda',
    year: 2001,
    miles: 50000
});
civic.toString();