Question

Write a JS function which receives a class and attaches to it a property species and a function toSpeciesString(). When called, the function returns a string with format:

I am a <species>. <toString()>

The function toString is called from the current instance (call using this).

Input:

Your function will receive a class whose prototype it should extend.

Output:

There is no output, your function should only attach the properties to the given class’ prototype.

Example:

function extendClass(classToExtend) {
    //TODO
}

 

Answer 1

My solution:

class Person {
    constructor(name, email) {
        this.name = name;
        this.email = email;
    }

    toString() {
        let className = this.constructor.name;
        return `${className} (name: ${this.name}, email: ${this.email})`;
    }
}

function extendClass(classToExtend) {

    classToExtend.prototype.species = 'Human';
    classToExtend.prototype.toSpeciesString = function () {
        return `I am a ${this.species}. ${this.toString()}`;
    }
}


extendClass(Person);
let gosho = new Person('gosho', 'email@soemthing.com');
console.log('' + gosho);
console.log(gosho.toSpeciesString());