Printing Objects in JavaScript in JavaScript

class Cat {
    constructor(name) {
        this.name = name;
    }

    toString() {
        return "Cat named " + this.name;
    }
}

console.log(String(new Cat("Tom")));   // Cat named Tom

Full lesson:

Every object already has a toString method. The default one isn't much use. It gives the same text for every object:

[object Object]

Write a toString method in your class, and it replaces the default. It returns the text that stands for the object.

JavaScript calls it whenever the object becomes a string. String(tom) does that. So do `I have ${tom}` and "I have " + tom.

There is one catch. console.log(tom) alone doesn't call toString. It shows the object's fields instead, like Cat { name: 'Tom' }. Turn the object into a string first.

toString takes no parameters. It must return the text, not print it.

Your task

The Dog class below has a name and an age. Add a toString method to it.

It returns the name, then " is ", the age and " years old". The code at the bottom prints String(rex) and String(bella).

Expected output:

Rex is 3 years old
Bella is 5 years old