Next button and Instruction check boxes stuck

Hi All,

I am on the 5/15 lessons on Learn Node.js:

I completed Instruction 1: module.exports = class Cat
but the check box didn’t change, and the rest of the instructions remained grey. I checked the hint and saw that my line was correct. Since I could still read the greyed out instructions, I continued to Instruction 2: module.exports = class Dog (compared it with the hint)
And in Instruction 3 wrote the two require():
// Require modules in:

let Dog = require(’./dog.js’);

let Cat = require(’./cat.js’);

Then I called node app.js and received a result for the “dog-cat fight”.
I did this page several times, refreshed it, and got “Rex wins!”, and then “Taby wins!” and no error message:
node app.js Tabby wins!
But no change and the Next button remains stuck.

Please help!

Sounds frustrating. Not sure what the issue is without all the code, but I thought I would share mine and see if it helps.


module.exports = class Cat {
  constructor(name, clawStrength) { = name;
    this.clawStrength = clawStrength;


module.exports = class Dog {
  constructor(name, toothStrength) { = name;
    this.toothStrength = toothStrength;


// Require modules in:

const Dog = require('./dog.js');
const Cat = require('./cat.js')

let fight = (dog, cat) => {
    if (dog.toothStrength > cat.clawStrength) {
        console.log(`${} wins!`);
    else if (dog.toothStrength < cat.clawStrength) {
        console.log(`${} wins!`);
    else {
        console.log(`${} and ${} are equally skilled fighters!`);


const myDog = new Dog('Rex', Math.random());
const myCat = new Cat('Tabby', Math.random());

fight(myDog, myCat);

This passed for me. If you can spot any differences, maybe we can figure out what’s going wrong.

1 Like

Hi Brian,

Thank you so much for the response, and for sharing the code. I also got Rex and then Taby!
I don’t know why it happened. I refreshed the browser several times.
But then, today it did go through.

Thank you so much!